@article{salem_debnath_agate_arafat_jameel_lucia_pal_2024, title={Development of multifunctional sustainable packaging from acetylated cellulose micro-nanofibrils (CMNF)}, volume={7}, ISSN={["2666-8939"]}, DOI={10.1016/j.carpta.2024.100421}, abstractNote={Cellulose micro-nanofibrils (CMNF) with different fibrillation levels were partially acetylated while preserving their morphological and native crystalline structure. The morphological changes due to fibrillation and chemical modification were observed using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and optical profilometry. The change in tensile and burst strength, barrier, and biodegradability profile were investigated which revealed that the mechanical properties of the unmodified CMNF films increased with increase in extent of fibrillation. However, the mechanical strength of the acetylated film decreased with the increase in degree of acetylation. The stretching or folding property of the film increased with the increase in both the fibrillation and acetylation. The contact angle value increased due to a higher degree of fibrillation and acetylation because they increased the hydrophobicity and consequently enhanced the air and water vapor resistance of the unmodified and modified CNF films. Furthermore, all films exhibited the highest resistance against oil and grease, and the biodegradability test substantiated that CNF films were compostable in soil. In total, this work expresses new pathways to enhance the barrier properties of biodegradable CNF films by regulating the degree of fibrillation and acetylation, thus can emerge as sustainable alternatives to for packaging and agriculture applications.}, journal={CARBOHYDRATE POLYMER TECHNOLOGIES AND APPLICATIONS}, author={Salem, Khandoker Samaher and Debnath, Mrittika and Agate, Sachin and Arafat, Kazi Md. Yasin and Jameel, Hasan and Lucia, Lucian and Pal, Lokendra}, year={2024}, month={Jun} }
 @article{salem_kasera_rahman_jameel_habibi_eichhorn_french_pal_lucia_2023, title={Comparison and assessment of methods for cellulose crystallinity determination}, volume={52}, ISSN={0306-0012 1460-4744}, url={http://dx.doi.org/10.1039/D2CS00569G}, DOI={10.1039/d2cs00569g}, abstractNote={The degree of crystallinity in cellulose significantly affects the physical, mechanical, and chemical properties of cellulosic materials, their processing, and their final application. Measuring the crystalline structures of cellulose is a challenging task due to inadequate consistency among the variety of analytical techniques available and the lack of absolute crystalline and amorphous standards. Our article reviews the primary methods for estimating the crystallinity of cellulose, namely, X-ray diffraction (XRD), nuclear magnetic resonance (NMR), Raman and Fourier-transform infrared (FTIR) spectroscopy, sum-frequency generation vibrational spectroscopy (SFG), as well as differential scanning calorimetry (DSC), and evolving biochemical methods using cellulose binding molecules (CBMs). The techniques are compared to better interrogate not only the requirements of each method, but also their differences, synergies, and limitations. The article highlights fundamental principles to guide the general community to initiate studies of the crystallinity of cellulosic materials.}, number={18}, journal={Chemical Society Reviews}, publisher={Royal Society of Chemistry (RSC)}, author={Salem, Khandoker Samaher and Kasera, Nitesh Kumar and Rahman, Md. Ashiqur and Jameel, Hasan and Habibi, Youssef and Eichhorn, Stephen J. and French, Alfred D. and Pal, Lokendra and Lucia, Lucian A.}, year={2023}, pages={6417–6446} }
 @article{salem_barrios_jameel_pal_lucia_2023, title={Computational and experimental insights into the molecular architecture of water-cellulose networks}, volume={6}, ISSN={2590-2385}, url={http://dx.doi.org/10.1016/j.matt.2023.03.021}, DOI={10.1016/j.matt.2023.03.021}, abstractNote={The current perspective attempts to provide key insights into several major aspects of water solvation supported by several experimental and computational investigations. It is postulated that water is not just a common solvent from the framework of the molecular level, but in fact can play the role of a co-reactant or induce an “organizational constraint” (e.g., crystallization) to regulate the rate of chemical reactions. The focus of our perspective is to provide insight into these phenomena; we will cast our net toward the formation of putative water molecules' stacking around the three-dimensional network of the cellulose, the most abundant biomaterial on the planet, which is further mitigated by hydrogen bonding and water-cellulose molecular architecture on the morphology, properties, and chemical reactivity of micro- and nanocellulose. Our perspective also introduces the idea of water hydration shells present immediate to the hydrophilic surface of the cellulose that can help articulate water chemistry and the challenges it presents during drying.}, number={5}, journal={Matter}, publisher={Elsevier BV}, author={Salem, Khandoker Samaher and Barrios, Nelson and Jameel, Hasan and Pal, Lokendra and Lucia, Lucian}, year={2023}, month={May}, pages={1366–1381} }
 @article{brito_suarez_pifano_reisinger_wright_saloni_kelley_gonzalez_venditti_jameel_2023, title={Environmental Life Cycle Assessment of Premium and Ultra Hygiene Tissue Products in the United States}, volume={18}, ISSN={["1930-2126"]}, DOI={10.15376/biores.18.2.4006-4031}, abstractNote={Under the controversial concern of using virgin fibers in hygiene tissue products, mostly Bleached Eucalyptus Kraft (BEK) and Northern Bleached Softwood Kraft (NBSK), consumers are responding by purchasing self-labeled sustainable products. As of today, there are no established sustainability reported results to inform consumers about the carbon footprint of hygiene tissue. To fill this gap, this study used Life Cycle Assessment to evaluate the environmental impacts across the supply chain (cradle to gate) to produce Premium and Ultra grades of bath tissue, including the production of feedstock, pulp production, and tissue production stages, with focus on Global Warming Potential (GWP). The results showed that one air-dried metric ton (ADmt) of BEK pulp had an associated GWP of 388 kgCO2eq, whereas one ADmt of NBSK pulp presented values ranging between 448 and 596 kgCO2eq, depending on the emissions allocation methodology used. It was estimated that the GWP of one finished metric ton of tissue weighted average could range from 1,392 to 3,075 kgCO2eq depending on mill location, electricity source, and machine technology. These results provide an understanding of the factors affecting the environmental impact of hygiene tissue products, which could guide manufacturers and consumers on decisions that impact their carbon footprint.}, number={2}, journal={BIORESOURCES}, author={Brito, Amelys and Suarez, Antonio and Pifano, Alonzo and Reisinger, Lee and Wright, Jeff and Saloni, Daniel and Kelley, Stephen and Gonzalez, Ronalds and Venditti, Richard and Jameel, Hasan}, year={2023}, month={May}, pages={4006–4031} }
 @article{vera_zambrano_marquez_vivas_forfora_bedard_farrell_ankeny_pal_jameel_et al._2023, title={Environmentally friendly oxidation pretreatments to produce sugar-based building blocks from dyed textile wastes via enzymatic hydrolysis}, volume={467}, ISSN={["1873-3212"]}, DOI={10.1016/j.cej.2023.143321}, abstractNote={Given the increasing concern over textile waste management and the proliferation of textile landfills, enzymatic hydrolysis of cotton represents a potential pathway to upcycle textile waste into valuable chemical building blocks. However, this pathway is challenged by the presence of persistent dyes, hindering enzyme performance. To overcome this issue, environmentally friendly and total chlorine free oxidation methods such as ozone and alkaline hydrogen peroxide were used in combination with mechanical refining pretreatment. The results showed that the enzymatic conversion of black-dyed cotton, without oxidation, resulted in a glucose yield of only 60% as compared to 95% for undyed cotton fibers. On the other hand, the inclusion of oxidation processes in the pretreatment stage resulted in a glucose yield of 90% via enzymatic hydrolysis at expense of using low oxidation chemicals and low enzyme charges. This work highlights the potential of oxidation methods, enzymatic hydrolysis, and mechanical refining as an ecofriendly pathway for generating value-added chemicals from cotton textile waste while promoting economic circularity.}, journal={CHEMICAL ENGINEERING JOURNAL}, author={Vera, Ramon E. and Zambrano, Franklin and Marquez, Ronald and Vivas, Keren A. and Forfora, Naycari and Bedard, John and Farrell, Matthew and Ankeny, Mary and Pal, Lokendra and Jameel, Hasan and et al.}, year={2023}, month={Jul} }
 @article{sulis_jiang_yang_marques_matthews_miller_lan_cofre-vega_liu_sun_et al._2023, title={Multiplex CRISPR editing of wood for sustainable fiber production}, volume={381}, ISSN={["1095-9203"]}, url={http://europepmc.org/abstract/med/37440632}, DOI={10.1126/science.add4514}, abstractNote={The domestication of forest trees for a more sustainable fiber bioeconomy has long been hindered by the complexity and plasticity of lignin, a biopolymer in wood that is recalcitrant to chemical and enzymatic degradation. Here, we show that multiplex CRISPR editing enables precise woody feedstock design for combinatorial improvement of lignin composition and wood properties. By assessing every possible combination of 69,123 multigenic editing strategies for 21 lignin biosynthesis genes, we deduced seven different genome editing strategies targeting the concurrent alteration of up to six genes and produced 174 edited poplar variants. CRISPR editing increased the wood carbohydrate-to-lignin ratio up to 228% that of wild type, leading to more-efficient fiber pulping. The edited wood alleviates a major fiber-production bottleneck regardless of changes in tree growth rate and could bring unprecedented operational efficiencies, bioeconomic opportunities, and environmental benefits. Description Editor’s summary Trees provide an important natural resource, but breeding for optimal wood properties is time consuming and hindered by the complexity of tree genetics and diversity. Sulis et al. show that CRISPR technologies can be readily deployed to enhance wood properties and augment the sustainability of forest trees (see the Perspective by Zuin Zeidler). The authors generated multiplexed genetic alterations modifying wood composition in poplar with more desirable traits for fiber pulping and lower carbon emissions. This work demonstrates that genome editing can be harnessed for breeding more efficient trees, which will provide timely opportunities for sustainable forestry and a more efficient bioeconomy. —DJ Gene editing enables precise woody-feedstock design to enhance fiber production efficiency and sustainability in poplar trees.}, number={6654}, journal={SCIENCE}, author={Sulis, Daniel B. and Jiang, Xiao and Yang, Chenmin and Marques, Barbara M. and Matthews, Megan L. and Miller, Zachary and Lan, Kai and Cofre-Vega, Carlos and Liu, Baoguang and Sun, Runkun and et al.}, year={2023}, month={Jul}, pages={216-+} }
 @article{jiang_wan_kollman_jiang_wu_jameel_chang_2023, title={Role of extractable lignin in enzymatic hydrolysis of hydrothermally pretreated hardwood}, volume={193}, ISSN={["1872-633X"]}, DOI={10.1016/j.indcrop.2022.116150}, abstractNote={The role of solvent extractable lignin in enzymatic hydrolysis of hydrothermally pretreated sweetgum was investigated. Lignin extraction with acetone, methanol or acetone/methanol removed 27–33% of lignin in hydrothermally pretreated sweetgum pulp, resulting in total sugar yield reduction. Comprehensive characterization indicated that the extractable lignin is highly degraded with low molecular weight, high phenolic hydroxyls, and low native lignin interunit linkages and exhibited neither stimulation nor inhibition effects on enzymatic hydrolysis of filter paper, Avicel, and bleached eucalyptus kraft pulp. The extractable lignin was mainly deposited on the surface of the fibers and pores, which removal caused significant morphological change and collapse of the mesopores and macropores. Thus, the reduction in enzymatic digestion efficiency was more likely caused by the pore collapse in fiber and decreased accessible area, rather than the stimulative action of the extractable lignin.}, journal={INDUSTRIAL CROPS AND PRODUCTS}, author={Jiang, Xiao and Wan, Shanqi and Kollman, Matthew and Jiang, Huicong and Wu, Shufang and Jameel, Hasan and Chang, Hou-min}, year={2023}, month={Mar} }
 @article{jiang_sun_kollman_chang_jameel_2023, title={Structure and property variations of mixed hardwood kraft lignins}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2023.2262974}, abstractNote={Abstract Kraft lignin as an emerging renewable feedstock can be used to produce fuels, chemicals, and materials. Hardwood kraft lignin bears intrinsic variation due to wood species and the isolation process. The structure and property variation of hardwood kraft lignin could introduce new challenges and opportunities for its application. To better understand such variation, seven kraft lignin samples, originated from southern mixed hardwood (North America), northern mixed hardwood (North America), and Asian mixed hardwood, were isolated from commercial kraft pulping black liquor using both LignoBoost and LignoForce processes. Modern analytical techniques were used to elucidate the characteristics of mixed hardwood kraft lignins, including chemical composition, molecular weight, functional groups, and thermal properties. All lignin samples had a lignin content over 90% (92% to 96%) with one exception, which was northern mixed hardwood kraft lignin with 86% of lignin content and 6% polysaccharides. The elemental and methoxy analyses revealed the expected variation of hardwood kraft lignins with the methoxy content ranging from 0.85 to 1.20 per C9 unit. The weight average molecular weight exhibited a higher variation (from 4800 to 1895 Da) with a descending order of southern mixed hardwood kraft lignins, northern mixed hardwood lignins, and Asian mixed hardwood lignins. The aliphatic hydroxy groups ranged from 14 to 25 per 100 C9 units, and phenolic hydroxy groups ranged from 65 to 112 per 100 C9 units. The catecholic group content ranged from 12 to 34 per 100 C9 units, which is higher than softwood kraft lignin. The lignins isolated from the rapid displacement heating (RDH) pulping process were more condensed than from the regular kraft pulping process. 2D HSQC and quantitative 13C NMR revealed the drastic structure change upon kraft pulp with the low abundance of native lignin linkages and formation of new interunit linkages, such as stilbene, enol ethers, and 1-1’/5’. The S/G ratio was calculated using 2D HSQC spectra correcting for signal shift caused by the catecholic groups.}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Jiang, Xiao and Sun, Runkun and Kollman, Matthew and Chang, Hou-min and Jameel, Hasan}, year={2023}, month={Sep} }
 @article{zwilling_whitham_zambrano_pifano_grunden_jameel_venditti_gonzalez_2023, title={Survivability of Salmonella Typhimurium (ATCC 14208) and Listeria innocua (ATCC 51742) on lignocellulosic materials for paper packaging}, volume={9}, ISSN={["2405-8440"]}, DOI={10.1016/j.heliyon.2023.e14122}, abstractNote={Lignocellulosic materials are widely used for food packaging due to their renewable and biodegradable nature. However, their porous and absorptive properties can lead to the uptake and retention of bacteria during food processing, transportation, and storage, which pose a potential risk for outbreaks of foodborne disease. Thus, it is of great importance to understand how bacteria proliferate and survive on lignocellulosic surfaces. The aim of this research was to compare the growth and survivability of Salmonella Typhimurium and Listeria innocua on bleached and unbleached paper packaging materials. Two different paper materials were fabricated to simulate linerboard from fully bleached and unbleached market pulps and inoculated with each bacterium at high bacterial loads (107 CFU). The bacteria propagated during the first 48 h of incubation and persisted at very high levels (>107 CFU/cm2) for 40 days for all paper and bacterium types. However, the unbleached paper allowed for a greater degree of bacterial growth to occur compared to bleached paper, suspected to be due to the more hydrophobic nature of the unbleached, lignin-containing fibers. Several other considerations may also alter the behavior of bacteria on lignocellulosic materials, such as storage conditions, nutrient availability, and chemical composition of the fibers.}, number={3}, journal={HELIYON}, author={Zwilling, Jacob D. and Whitham, Jason and Zambrano, Franklin and Pifano, Alonzo and Grunden, Amy and Jameel, Hasan and Venditti, Richard and Gonzalez, Ronalds}, year={2023}, month={Mar} }
 @article{salem_jameel_lucia_pal_2023, title={Sustainable high-yield lignocellulosic fibers and modification technologies educing softness and strength for tissues and hygiene products for global health}, volume={22}, ISSN={["2589-2347"]}, DOI={10.1016/j.mtsust.2023.100342}, abstractNote={Unbleached hardwood kraft pulp was treated with a non-ionic surfactant to decrease the concentration of a hydration shell by dislodging hard-to-remove water through a targeted reduction in surface tension. Energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry techniques were used to investigate and evaluate these fiber-surfactant interactions. Scanning electron microscopeimages were taken to observe the change in the morphology from the surfactant treatment. The surface tension was measured by using pendant drop tests, which reduced from 71.46 mN/m to ∼ 49–51 mN/m for different pretreatment techniques and hence, reduced the pulling force exerted by the liquid bridge water on the fibers by 28–31%. This consequently led to reduced fiber collapse, and the surfactant-treated fibers showed higher bulk and softness without a concomitant sacrifice of mechanical properties. The scanning electron microscopeimages confirmed a more cylindrical fiber structure and showed an unaffected fiber–fiber interaction because of which the tensile strength was not compromised with the increase of bulk. The surfactant-treated fibers showed better recovery or spring back, i.e. a return to their original form after compression relative to the untreated fibers. Therefore, it was possible to make tissue papers with higher bulk, softer hand-feel, and a higher absorbing capacity, without reducing the tensile strength by simple and green processes involving chemical and mechanical modifications.}, journal={MATERIALS TODAY SUSTAINABILITY}, author={Salem, K. S. and Jameel, H. and Lucia, L. and Pal, L.}, year={2023}, month={Jun} }
 @article{kollman_jiang_sun_zhang_li_chang_jameel_2023, title={Towards jet fuel from technical lignins: Feedstock-catalyst-product interactions revealed during catalytic hydrogenolysis}, volume={451}, ISSN={["1873-3212"]}, DOI={10.1016/j.cej.2022.138464}, abstractNote={One-pot conversion of technical lignins to jet fuel is limited by recondensation of unstable intermediates. A two-stage process that first generates stabilized fragments by reductive depolymerization, then upgrades oligomers to hydrocarbons may increase yield. Insights into factors affecting initial depolymerization of industrially relevant lignins were revealed, whereas many studies have focused on upgrading bio-oil or model compounds. Feedstocks, catalysts, and process conditions were varied to identify effects on product composition. Hydrogen and temperature synergistically suppressed coking during pine kraft depolymerization to increase monomer production. Ruthenium was more effective than cobalt at limiting solid residue and improving liquid product yield by promoting hydrogenation and hydrogenolysis. Besides ruthenium, a strong acid-base catalyst effectively deconstructed hardwood biorefinery lignin, targeting alkyl-aryl ether bonds. Ruthenium and zinc converted hardwood kraft lignin to oligomers most suitable for upgrading to jet fuel-range hydrocarbons based on yield (79 % on dry lignin), weight-average molecular weight (1290 g/mol), and chemical structure.}, journal={CHEMICAL ENGINEERING JOURNAL}, author={Kollman, Matthew S. and Jiang, Xiao and Sun, Runkun and Zhang, Xia and Li, Wenzhi and Chang, Hou-min and Jameel, Hasan}, year={2023}, month={Jan} }
 @article{vera_vivas_urdaneta_franco_sun_forfora_frazier_gongora_saloni_fenn_et al._2023, title={Transforming non-wood feedstocks into dissolving pulp via organosolv pulping: An alternative strategy to boost the share of natural fibers in the textile industry.}, volume={429}, ISSN={["1879-1786"]}, url={https://doi.org/10.1016/j.jclepro.2023.139394}, DOI={10.1016/j.jclepro.2023.139394}, abstractNote={This work evaluates wheat straw, switchgrass, and hemp hurd as potential alternatives for producing dissolving pulp using sulfur dioxide (SO2)-ethanol-water (SEW) pulping. The SEW process is described in detail for wheat straw, and the best pulping conditions for this feedstock were 130 °C, 4 h, and 10% SO2 concentration, comprised in a sulfur-ethanol-water ratio of 10-45-45. This resulted in a viscose-grade pulp with 93% α-cellulose, 2.0% hemicelluloses, <0.1% lignin, 0.2% ash content, and a viscosity of 4.7 cP. The best pulping conditions for wheat straw were applied to switchgrass and hemp hurd. Wheat straw and switchgrass had similar pulp quality, while hemp hurd pulp had a higher hemicellulose content and lower viscosity. This work suggests that non-wood feedstocks such as wheat straw and switchgrass can be promising alternatives for dissolving pulp production, which can help reduce the pressure on the textile industry to increase the use of natural fibers and mitigate the environmental impact of non-biodegradable synthetic fibers.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Vera, Ramon E. and Vivas, Keren A. and Urdaneta, Fernando and Franco, Jorge and Sun, Runkun and Forfora, Naycari and Frazier, Ryen and Gongora, Stephanie and Saloni, Daniel and Fenn, Larissa and et al.}, year={2023}, month={Dec} }
 @article{vera_suarez_zambrano_marquez_bedard_vivas_pifano_farrell_ankeny_jameel_et al._2023, title={Upcycling cotton textile waste into bio-based building blocks through an environmentally friendly and high-yield conversion process}, volume={189}, ISSN={["1879-0658"]}, url={https://doi.org/10.1016/j.resconrec.2022.106715}, DOI={10.1016/j.resconrec.2022.106715}, abstractNote={This work presents mechanical refining as a chemical-free pretreatment of cotton textile waste to be converted into glucose via enzymatic hydrolysis. Both Cellic® CTec2 and CTec3 cellulase enzymes were evaluated to perform the enzymatic hydrolysis. Mechanical refining enabled cotton fiber fibrillation, thus increasing its specific surface area, water swellability, enzyme adsorption, and the efficiency of cotton conversion into sugars. Compared to conventional pretreatments, mechanical refining promoted sugar yields above 90% after enzymatic hydrolysis at lower enzyme usage (4–6 FPU/O.D g). From experimental data, a non-linear model was developed to predict cotton conversion. The predictive model allowed the optimization of the conversion process, which resulted in maximum yields of 89.3 and 98.3% when CTec2 and CTec3 were respectively used. Results from this work open the window to deploy mechanical refining as a promising and more sustainable transformation approach to produce sugar-based building blocks within the circular economy framework of textile waste.}, journal={RESOURCES CONSERVATION AND RECYCLING}, author={Vera, Ramon E. and Suarez, Antonio and Zambrano, Franklin and Marquez, Ronald and Bedard, John and Vivas, Keren A. and Pifano, Alonzo and Farrell, Matthew and Ankeny, Mary and Jameel, Hasan and et al.}, year={2023}, month={Feb} }
 @article{londono-zuluaga_jameel_gonzalez_nellenbach_brown_yang_lucia_2022, title={A Unique Crustacean-Based Chitin Platform to Reduce Self-Aggregation of Polysaccharide Nanofibers}, volume={10}, ISSN={["2079-6439"]}, url={https://www.mdpi.com/2079-6439/10/10/87}, DOI={10.3390/fib10100087}, abstractNote={Every year, over 8 million tons of crustacean shells are discarded. However, there exists an opportunity for valorizing the chitin and calcium carbonate part of the composition of the shells. Our study revealed crustacean chitin reduces self-aggregation effects. It was shown that crustacean-based nanofibers alone or added to cellulose offer unprecedented reductions in viscosity even after drying to produce foams impossible for cellulose. Polysaccharide nanofibers suffer from increased viscosity from strong hydrogen bonding addressed by the incorporation of crustacean-based nanofibers. The ability of the nanocomposite to overcome self-aggregation and collapse was attributed to organized chitin nanofiber morphology in the crustacean matrix. As a result of enhanced surface area from reduced fiber aggregation, the chitin/crustacean-cellulose blend was tested for a biomedical application requiring a high surface area: coagulation. Preliminary experiments showed the crustacean matrices, especially those containing calcium carbonate, induced blood clotting when 35 s. A materials platform is proposed for bio-based nanofiber production overcoming intractable and difficult-to-address self-aggregation effects associated with polysaccharides.}, number={10}, journal={FIBERS}, author={Londono-Zuluaga, Carolina and Jameel, Hasan and Gonzalez, Ronalds and Nellenbach, Kimberly and Brown, Ashley and Yang, Guihua and Lucia, Lucian}, year={2022}, month={Oct} }
 @article{salem_naithani_jameel_lucia_pal_2022, title={A systematic examination of the dynamics of water-cellulose interactions on capillary force-induced fiber collapse}, volume={295}, ISSN={["1879-1344"]}, url={http://dx.doi.org/10.1016/j.carbpol.2022.119856}, DOI={10.1016/j.carbpol.2022.119856}, abstractNote={Cellulosic fiber collapse is a phenomenon of fundamental importance for many technologies that include tissue/hygiene to packaging because it governs their essential materials properties such as tensile strength, softness, and water absorption; therefore, we elaborate cellulose fiber collapse from water interactions. This is the first attempt to directly correlate fiber collapse and entrapped or hard-to-remove (HR) water content through DSC, TGA and SEM. Freeze-drying and oven drying were individually investigated for influence on collapse. SEM of the fibers at different moisture contents show that irreversible collapsing begins as entrapped water departs the fiber surface. The removal of HR water pulls cell walls closer due to strong capillary action which overwhelms the elastic force of the fiber lumen which results in partially or fully irreversible collapse. The initial moisture content and refining intensity were found to regulate HR water content and consequently played a vital role in fiber collapsing.}, journal={CARBOHYDRATE POLYMERS}, publisher={Elsevier BV}, author={Salem, Khandoker Samaher and Naithani, Ved and Jameel, Hasan and Lucia, Lucian and Pal, Lokendra}, year={2022}, month={Nov} }
 @article{buitrago-tello_venditti_jameel_yao_echeverria_2022, title={Carbon Footprint of Bleached Softwood Fluff Pulp: Detailed Process Simulation and Environmental Life Cycle Assessment to Understand Carbon Emissions}, volume={10}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/acssuschemeng.2c00840}, DOI={10.1021/acssuschemeng.2c00840}, abstractNote={Wood-based fluff pulp (FP) is the primary raw material for indispensable commodities, including hygienic products. FP substantially contributes to global warming due to the high manufacturing energy demand. Despite FP’s importance, the environmental implications of its manufacture have not been transparently explored. The present study provides the carbon footprint for FP cradle-to-manufacturing gate based on process simulation and environmental life cycle assessment The simulation tracks the anthropogenic and biogenic carbon across the mill’s areas. In addition, the implications of switching energy sources and key operational conditions are evaluated. The results show that 1 kg of FP produces 1.102 kg CO2-equiv. Most of the biogenic carbon fed to the mill (52%) is used to produce steam and electricity. The study shows that switching from natural gas to residual biomass wood pellets represents a reduction of 13.4% of the CO2-equiv emissions. This benefit is increased if wood pellets are used to achieve electrical power self-sufficiency, and even more benefit can be realized if the mill produces 20% surplus electricity to the grid. A critical parameter for global warming potential is the incoming biomass lignin content; the pulping of biomass with higher lignin content produces a black liquor with higher heating value and more solids burned in the recovery boiler, reducing the demand for external energy and thus reducing fossil-based greenhouse gas emissions.}, number={28}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Buitrago-Tello, Rodrigo and Venditti, Richard A. and Jameel, Hasan and Yao, Yuan and Echeverria, Darlene}, year={2022}, month={Jul}, pages={9029–9040} }
 @article{zambrano_marquez_vera_jameel_venditti_gonzalez_2022, title={Developing Alternative, High-Absorbency Brown Fibers: Tissue Paper from Upcycled Corrugated Packaging Waste to Meet New Consumer Trends}, volume={9}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.2c03280}, DOI={10.1021/acssuschemeng.2c03280}, abstractNote={Consumers’ rising interest in brown tissue papers, perceived as sustainable, has increased the market share and selling prices of such products despite their limited performance. Meanwhile, the current excess of packaging waste in the US has created an opportunity for using old corrugated containerboard (OCC) as an alternative source of brown pulp, despite its inferior tissue-making characteristics relative to bleached fibers. Strength, water absorption capacity, and absorption rate are among the crucial properties of absorbent tissue products. Herein, we studied the feasibility of total chlorine-free treatments, namely, oxygen delignification, alkaline hydrogen peroxide, and ozonation, to improve the tissue-making quality of OCC pulp. The processes evaluated reduced the lignin content (kappa number from 89 to values as low as 55) and generated brightness gains as high as 8.8% ISO units. The strength of the sheets also improved due to the delignification and increase in fiber swelling. Chemically treated OCC resulted in sheets with higher water absorption capacity and absorption rate and fiber slurries with higher freeness compared to sheets and slurries from mechanically refined OCC. Therefore, we demonstrate the application of treatments with low environmental impact to upcycle OCC into a high-quality brown pulp suitable for manufacturing high-performance tissue paper.}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Zambrano, Franklin and Marquez, Ronald and Vera, Ramon and Jameel, Hasan and Venditti, Richard and Gonzalez, Ronalds}, year={2022}, month={Sep} }
 @article{park_cruz_tiller_johnson_mittal_jameel_venditti_park_2022, title={Effect of ash in paper sludge on enzymatic hydrolysis}, volume={165}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2022.106567}, DOI={10.1016/j.biombioe.2022.106567}, abstractNote={The valorization of paper sludge is a high-potential process to develop renewable fuels and chemicals, which can be integrated with pulp and paper mills. Calcium carbonate is the main ash component in sludge, which plays a role in buffering pH and potentially lowering the conversion during enzymatic hydrolysis. Therefore, it is important to investigate the effect of ash on sugar yields and examine pH change to introduce efficient and economical enzymatic hydrolysis of sludge. Carbohydrate conversion was enhanced when the ash was removed by fractionation. On the other hand, the highest sugar recovery was obtained when the sludge contained 20% ash content. The pH change during enzymatic hydrolysis was influenced by ash and explained why sludge-derived hydrolysate showed lower carbohydrate conversion. Therefore, a high shear process with the increased acid amount is suggested to prohibit the negative effect of ash and enhance the accessibility of cellulase to fibers. This study highlights the feasibility of using wet waste streams generated by the paper industry.}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Park, Hyeonji and Cruz, David and Tiller, Phoenix and Johnson, David K. and Mittal, Ashutosh and Jameel, Hasan and Venditti, Richard and Park, Sunkyu}, year={2022}, month={Oct}, pages={106567} }
 @article{kumar_zambrano_peszlen_venditti_pawlak_jameel_gonzalez_2022, title={High-performance sustainable tissue paper from agricultural residue: a case study on fique fibers from Colombia}, volume={6}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-022-04687-3}, abstractNote={Global sustainability megatrends are promoting the utilization of sustainably perceived fibers such as recycled and agricultural residue fibers in hygiene tissue applications. Tissue paper products advertised as sustainable have higher prices and inferior performance than conventional products manufactured from virgin wood fibers. This work demonstrates the feasibility of using agricultural residues from fique plantations (Furcraea microphylla genus) as an alternative to Northern Bleached Softwood Fibers (NBSK) in high-performance hygiene tissue applications. For our study, fiber residues were mechanically cleaned and upgraded to a tissue pulp using a simple pulping and bleaching process. A complete characterization of tissue paper properties (bulk, softness, water absorbency, tensile strength) was performed and compared against the NBSK market pulp. Additionally, fique residue pulp was blended with Bleached Eucalyptus Kraft (BEK) to match the performance of a selected benchmark consisting of 70% BEK and 30% NBSK. Results indicate fique residue bleached pulp has similar fiber morphology and comparable strength properties in terms of the tensile strength (+ 6%) and tear strength (+ 10%), but superior bulk (+ 12%), water absorbency (+ 28%), and softness (−29% TS7 values) than NBSK pulp. A fiber blend of 70% BEK and 30% fique residue showed superior tensile strength (+ 21%), tear strength (+ 54%), bulk (+ 5.5%), water absorbency (+ 1.5%), and softness (−8.7% TS7 values) over a similar fiber blend of BEK and NBSK. Our findings demonstrate that fibers from fique residue can substitute NBSK in hygiene tissue applications. Upgrading residues from fique fibers as raw materials for the tissue industry can bridge the gap between sustainability and product performance, simultaneously opening the possibility of new revenue streams for millions of small farmers in the producing countries.}, journal={CELLULOSE}, author={Kumar, Rajnish and Zambrano, Franklin and Peszlen, Ilona and Venditti, Richard and Pawlak, Joel and Jameel, Hasan and Gonzalez, Ronalds}, year={2022}, month={Jun} }
 @article{huang_jiang_shen_hu_tang_wu_ragauskas_jameel_meng_yong_2022, title={Lignin-enzyme interaction: A roadblock for efficient enzymatic hydrolysis of lignocellulosics}, volume={154}, ISSN={["1879-0690"]}, DOI={10.1016/j.rser.2021.111822}, abstractNote={Efficiently producing second-generation biofuels from biomass is of strategic significance and meets sustainability targets, but it remains a long-term challenge due to the existence of biomass recalcitrance. Lignin contributes significantly to biomass recalcitrance by physically limiting the access of enzymes to carbohydrates, and this could be partially overcome by applying a pretreatment step to directly target lignin. However, lignin typically cannot be completely removed, and its structure is also significantly altered during the pretreatment. As a result, lignin residue in the pretreated materials still significantly hindered a complete conversion of carbohydrate to its monosugars by interacting with cellulase enzymes. The non-productive adsorption driven by hydrophobic, electrostatic, and/or hydrogen bonding interactions is widely considered as the major mechanism of action governing the unfavored lignin-enzyme interaction. One could argue this type of interaction between lignin residue and the activated enzymes is the major roadblock for efficient enzymatic hydrolysis of pretreated lignocellulosics. To alleviate the negative effects of lignin on enzyme performance, a deep understanding of lignin structural transformation upon different types of pretreatments as well as how and where does lignin bind to enzymes are prerequisites. In the last decade, the progress toward a fundamental understanding of lignin-enzyme interaction, structural characterization of lignin during pretreatment and/or conformation change of enzyme during hydrolysis is resulting in advances in the development of methodologies to mitigate the negative effect of lignin. Here in this review, the lignin structural transformation upon different types of pretreatments and the inhibition mechanism of lignin in the bioconversion of lignocellulose to bioethanol are summarized. Some technologies to minimize the adverse impact of lignin on the enzymatic hydrolysis, including chemical modification of lignin, adding blocking additives, and post-treatment to remove lignin were also introduced. The production of liquid biofuels from lignocellulosic biomass has shown great environmental benefits such as reducing greenhouse gas emissions and mitigate climate change. By addressing the root causes of lignin-enzyme interaction and how to retard this interaction, it is our hope that this comprehensive review will pave the way for significantly reducing the high cost associated with the enzymatic hydrolysis process, and ultimately achieving a cost-effective and sustainable biorefinery system.}, journal={RENEWABLE & SUSTAINABLE ENERGY REVIEWS}, author={Huang, Caoxing and Jiang, Xiao and Shen, Xiaojun and Hu, Jinguang and Tang, Wei and Wu, Xinxing and Ragauskas, Arthur and Jameel, Hasan and Meng, Xianzhi and Yong, Qiang}, year={2022}, month={Feb} }
 @article{marquez_zwilling_zambrano_tolosa_marquez_venditti_jameel_gonzalez_2022, title={Nanoparticles and essential oils with antiviral activity on packaging and surfaces: An overview of their selection and application}, volume={7}, ISSN={["1558-9293"]}, url={https://doi.org/10.1002/jsde.12609}, DOI={10.1002/jsde.12609}, abstractNote={Until recently, food packaging has been used as a barrier to unfavorable environmental and microbial conditions, but new technologies are arising aimed at upgrading the protective nature of these materials. Cases of bacterial and viral transmission through food and surfaces have shown the vulnerabilities of the food packaging distribution systems over the years, creating awareness about new methods to prevent the proliferation of pathogens. This has been highlighted by safety concerns due to the COVID‐19 pandemic. This work reviews the state‐of‐the‐art biobased technologies tailored for antiviral applications on surfaces, focusing on packaging materials. A survey and selection tool of essential oils (EOs) and nanoparticles that have been proven effective in reducing the proliferation or transmission of viruses through surfaces is presented. Additionally, the use of essential oil formulations or nanoparticle‐functionalized biobased materials that can be deployed to prevent virus transmission through food produce and surfaces is reviewed, including environmental and safety concerns around the use of metal nanoparticles and EOs in packaging materials. Finally, an assessment of the available technologies, challenges, opportunities and the potential role of biobased antiviral surfaces in future viral outbreaks is presented. [ FROM AUTHOR] Copyright of Journal of Surfactants & Detergents is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)}, journal={JOURNAL OF SURFACTANTS AND DETERGENTS}, publisher={Wiley}, author={Marquez, Ronald and Zwilling, Jacob and Zambrano, Franklin and Tolosa, Laura and Marquez, Maria E. and Venditti, Richard and Jameel, Hasan and Gonzalez, Ronalds}, year={2022}, month={Jul} }
 @article{echeverria_venditti_jameel_yao_2022, title={Process Simulation-Based Life Cycle Assessment of Dissolving Pulps}, volume={56}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/acs.est.1c06523}, DOI={10.1021/acs.est.1c06523}, abstractNote={Dissolving pulp (DP) is a specialty pulp product from a variety of lignocellulosic biomass (i.e., hardwoods (HW) and softwoods (SW)) with a broad range of applications. Conducting life cycle assessment (LCA) for DP end applications (e.g., textile products, specialty plastics) is challenging due to the lack of life cycle inventory (LCI) data and environmental information associated with different grades. This research addresses this challenge using process simulations to generate LCI for different DP grades (e.g., acetate and viscose) made from HW and SW, respectively. The LCA results show that biomass feedstock directly affects the environmental impacts of DP. For instance, HW acetate grade has higher global warming potential than SW acetate but lower environmental impacts in other categories related to ecosystems and human health. This HW versus SW comparison has similar results for viscose DP in all impact categories except eutrophication. Additionally, a hotspot analysis identifies that on-site emissions and chemicals are the main contributors to the environmental impacts across all grades in this study. The results and LCI data generated in this work provide critical information to support future LCA and sustainability assessment for end-products derived from DP.}, number={7}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Echeverria, Darlene and Venditti, Richard and Jameel, Hasan and Yao, Yuan}, year={2022}, month={Mar}, pages={4578–4586} }
 @article{jardim_hart_lucia_jameel_chang_2022, title={The Effect of the Kraft Pulping Process, Wood Species, and pH on Lignin Recovery from Black Liquor}, volume={10}, ISSN={["2079-6439"]}, url={https://www.mdpi.com/2079-6439/10/2/16}, DOI={10.3390/fib10020016}, abstractNote={Lignin has shown a great potential to produce fuels, value-added chemicals, and functional materials due to its high-energy density and intrinsic aromatic-based structure. Yet, the lignin precipitation of different biomasses needs investigation because most of the work has been performed on softwood and much less is known about hardwoods. In fact, the lignin from these two wooden biomasses vary in composition and pulping performance, which can reflect on lignin precipitation. Therefore, the present study investigated the precipitation and composition of 40 distinct kraft lignins obtained from pine, acacia, sweetgum, and eucalyptus black liquors. Two lignin fractions were precipitated at different pHs, according to known industrial lignin separation practices (pH = 9.5 and 2.5) from black liquors taken at different levels of pulping. Overall, lignin recovery increased with increasing lignin concentration in the black liquor, i.e., higher amounts of lignin were obtained at higher levels of delignification. In addition, pine lignins showed superior yields than the hardwoods and were around five times purer. Among the hardwoods, lignin recovery increased with the S–G ratio of the native lignin, and eucalyptus showed the best performance by achieving the highest yields and purities. Finally, the present work compared the lignin recovery yield and the purity of softwood and different hardwood lignins in a systematic way, which will increase awareness of this underutilized green material and could potentially increase the interest in establishing new lignin plants across the globe.}, number={2}, journal={FIBERS}, author={Jardim, Juliana M. and Hart, Peter W. and Lucia, Lucian A. and Jameel, Hasan and Chang, Hou-min}, year={2022}, month={Feb} }
 @article{echeverria_venditti_jameel_yao_2021, title={A general Life Cycle Assessment framework for sustainable bleaching: A case study of peracetic acid bleaching of wood pulp}, volume={290}, ISSN={0959-6526}, url={http://dx.doi.org/10.1016/j.jclepro.2021.125854}, DOI={10.1016/j.jclepro.2021.125854}, abstractNote={Bleaching is an important industrial operation that has significant environmental impacts. Many new bleaching technologies have been developed; nonetheless, it is challenging to quantify their potential environmental impacts due to the lack of quantitative information and robust analysis methods across different bleaching agents. This study addresses this gap by developing a general Life Cycle Assessment (LCA) framework that integrates LCA with manufacturing process simulations and lab-scale bleaching experiments. The framework was applied to a case study of Peracetic Acid (PAA), a promising bleaching agent, used in the Total Chlorine-Free (TCF) technology for wood pulp production, compared with the traditional Elemental Chlorine-Free (ECF) using chlorine dioxide. Different PAA synthetic pathways (i.e., using acetic acid or triacetin) and bleaching charges were explored using scenario analysis. Results showed that PAA-based TCF achieves a brightness similar to the conventional ECF technology with lower life-cycle impacts in categories such as global warming and eutrophication. From a process perspective, PAA-based TCF reduces the consumption of energy, water, pulping chemicals, completely avoids the use of chlorinated compounds, and provides enhanced process safety. The source of PAA significantly affects the life-cycle environmental impacts of pulp bleaching. Using PAA synthesized from triacetin rather than acetic acid leads to higher environmental impacts; however, such impacts can be mitigated by reducing excessive use of triacetin (direction for future optimization) or using bio-based glycerin in the production of the triacetin feedstock for PAA production. Although this case study focuses on PAA bleaching for wood pulp, the framework has the potential to be used for other/same bleaching agents in different industrial sectors.}, journal={Journal of Cleaner Production}, publisher={Elsevier BV}, author={Echeverria, Darlene and Venditti, Richard and Jameel, Hasan and Yao, Yuan}, year={2021}, month={Mar}, pages={125854} }
 @article{kollman_jiang_thompson_mante_dayton_chang_jameel_2021, title={Improved understanding of technical lignin functionalization through comprehensive structural characterization of fractionated pine kraft lignins modified by the Mannich reaction}, ISSN={["1463-9270"]}, DOI={10.1039/d1gc01842f}, abstractNote={Detailed investigation of structural changes following kraft lignin amination. Identification of factors that affected reaction route and yield, and evaluation of different characterization methods will aid kraft lignin applied research efforts.}, journal={GREEN CHEMISTRY}, author={Kollman, Matthew and Jiang, Xiao and Thompson, Samuel J. and Mante, Ofei and Dayton, David C. and Chang, Hou-min and Jameel, Hasan}, year={2021}, month={Aug} }
 @article{starkey_chenoweth_johnson_salem_jameel_pal_2021, title={Lignin-containing micro/nanofibrillated cellulose to strengthen recycled fibers for lightweight sustainable packaging solutions}, volume={2}, ISSN={["2666-8939"]}, url={http://dx.doi.org/10.1016/j.carpta.2021.100135}, DOI={10.1016/j.carpta.2021.100135}, abstractNote={As e-commerce drives the packaging growth, consumers are pushing for more sustainable packaging solutions. Considering the current societal needs, we have been able to engineer a new pathway for sustainable packaging solutions by developing lignin-containing micro- and nano-fibrillated cellulosic (LMNFCs) materials to strengthen the recycled fibers. LMNFCs from unbleached softwood pulp containing 14.4% lignin at high and low fibrillation levels were produced. Packaging papers from recycled old-corrugated containers were strengthened with LMNFCs with varying addition levels of 1 wt% to 3 wt% at two basis weights. The results show 2 wt% addition of LMNFC can enhance strength at low levels of fibrillation, and that basis weight can be reduced by 16.7%, from 150 gsm to 125 gsm, while maintaining a burst strength of 49-53 lbf. Reduction in basis weight and high lignin content of LMNFC also enhanced dewatering during sheet formation with the lowest increase in drainage time, 9%, relative to the 150 gsm with no LMNFC. The techno-economic analysis supports the feasibility of using LMNFC to produce lightweight and sustainable packaging materials at industrial scale with an 8% reduction in fiber cost.}, journal={CARBOHYDRATE POLYMER TECHNOLOGIES AND APPLICATIONS}, publisher={Elsevier BV}, author={Starkey, Heather and Chenoweth, Audra and Johnson, Christopher and Salem, Khandoker Samaher and Jameel, Hasan and Pal, Lokendra}, year={2021}, month={Dec} }
 @article{salem_naithani_jameel_lucia_pal_2021, title={Lignocellulosic Fibers from Renewable Resources Using Green Chemistry for a Circular Economy}, volume={5}, ISSN={["2056-6646"]}, url={https://doi.org/10.1002/gch2.202000065}, DOI={10.1002/gch2.202000065}, abstractNote={The sustainable development of lignocellulose fibers exhibits significant potential to supplant synthetic polymer feedstocks and offers a global platform for generating sustainable packaging, bioplastics, sanitary towels, wipes, and related products. The current research explores the dynamics of fiber production from wood, non‐wood, and agro‐residues using carbonate hydrolysis and a mild kraft process without bleaching agents. With respect to carbonate hydrolysis, high yield, and good coarseness fibers are attained using a simple, low‐cost, and ecofriendly process. Fibers produced using a mild kraft process have lower Klason lignin, carboxyl content, surface charges, and higher fiber length, and crystallinity. Eucalyptus fibers show the highest crystallinity while softwood carbonate fibers show the lowest crystallinity. Hemp hurd fibers contain the highest concentration of hard‐to‐remove water, and thus, suffer maximum flattening visualized by the microscopic images. The relatively high yield sustainable fibers with versatile properties can provide a significant economic benefit since fiber is the dominant cost for producing various bioproducts to meet society's current and future needs.}, number={2}, journal={GLOBAL CHALLENGES}, author={Salem, Khandoker S. and Naithani, Ved and Jameel, Hasan and Lucia, Lucian and Pal, Lokendra}, year={2021}, month={Feb} }
 @article{zambrano_wang_zwilling_venditti_jameel_rojas_gonzalez_2021, title={Micro- and nanofibrillated cellulose from virgin and recycled fibers: A comparative study of its effects on the properties of hygiene tissue paper}, volume={254}, ISSN={0144-8617}, url={http://dx.doi.org/10.1016/j.carbpol.2020.117430}, DOI={10.1016/j.carbpol.2020.117430}, abstractNote={This study aims to understand the effect of micro- and nanofibrillated cellulose (MNFC) on the tensile index, softness, and water absorbency of tissue paper. MNFC was produced from four different fiber sources. The results show that MNFC acts as an effective strength enhancer at the expense of a reduced water absorbency and softness. The impact of the fiber source on MNFC manufacturing cost and the trade-off with performance was also investigated. MNFCs produced from southern bleached hardwood kraft, northern bleached softwood kraft, and deinked pulp exhibited similar performance trends with the MNFC from the deinked pulp having a significantly lower cost. This suggests that MNFCs with similar degrees of fibrillation may be used interchangeably regardless of the fiber source, revealing the possibility to minimize MNFC manufacturing costs based on fiber selection. MNFC produced from bleached Eucalyptus kraft showed the lowest degree of fibrillation and the lowest strength improvements among the MNFCs evaluated.}, journal={Carbohydrate Polymers}, publisher={Elsevier BV}, author={Zambrano, Franklin and Wang, Yuhan and Zwilling, Jacob D. and Venditti, Richard and Jameel, Hasan and Rojas, Orlando and Gonzalez, Ronalds}, year={2021}, month={Feb}, pages={117430} }
 @article{jardim_hart_lucia_jameel_2021, title={Probing the molecular weights of sweetgum and pine kraft lignin fractions}, volume={20}, ISSN={["0734-1415"]}, DOI={10.32964/TJ20.6.381}, abstractNote={The present investigation undertook a systematic investigation of the molecular weight (MW) of kraft lignins throughout the pulping process to establish a correlation between MW and lignin recovery at different extents of the kraft pulping process. The evaluation of MW is crucial for lignin characterization and utilization, since it is known to influence the kinetics of lignin reactivity and its resultant physicochemical properties. 
Sweetgum and pine lignins precipitated from black liquor at different pHs (9.5 and 2.5) and different extents of kraft pulping (30–150 min) were the subject of this effort. Gel permeation chromatography (GPC) was used to deter-
mine the number average molecular weight (Mn), mass average molecular weight (Mw), and polydispersity of the lignin samples. It was shown that the MW of lignins from both feedstocks follow gel degradation theory; that is, at the onset of the kraft pulping process low molecular weightlignins were obtained, and as pulping progressed, the molecular weight peaked and subsequently decreased. An important finding was that acetobromination was shown to be a more effective derivatization technique for carbohydrates containing lignins than acetylation, the technique typically used for derivatization of lignin.}, number={6}, journal={TAPPI JOURNAL}, author={Jardim, Juliana M. and Hart, Peter W. and Lucia, Lucian and Jameel, Hasan}, year={2021}, month={Jun}, pages={381–391} }
 @article{assis_suarez_prestemon_stonebraker_carrillo_dasmohapatra_jameel_gonzalez_2021, title={Risk Analysis, Practice, and Considerations in Capital Budgeting: Evidence from the Field for the Bio-based Industry}, volume={16}, ISSN={["1930-2126"]}, url={http://dx.doi.org/10.15376/biores.16.1.19-45}, DOI={10.15376/biores.16.1.19-45}, abstractNote={This study aims to examine how organizations in the bio-based industry perceive risks and perform risk analysis within the capital investment decision-making process. More specifically, this study aims to assess sources of uncertainty commonly considered, identify tools and methods used for risk assessment, and understand how risk analysis is considered in capital budgeting. Eighty-six respondents were electronically surveyed on practices for capital investment risk analysis, including C-suite and upper management from different organization sizes and segments in the bio-based industry. It was found that some forms of risk analysis are utilized either in project assessment and/or for decision making by most respondents; however, qualitative and deterministic assessment practices dominate over probabilistic methods. In addition, risk assessment is most commonly performed in the later stages of a project, with less than 50% of adoption at the earlier stages. Overall, the main sources of uncertainties considered when performing risk assessment are financial, market and sales, and technology, with competition being considered mostly by upper management levels. Additionally, consistent with previous studies in other industry sectors, Internal Rate of Return, Return on Investment, and Net Present Value are the preferred financial indicators used to evaluate capital investments.}, number={1}, journal={BIORESOURCES}, publisher={BioResources}, author={Assis, Camilla Abbati and Suarez, Antonio and Prestemon, Jeffrey P. and Stonebraker, Jeffrey and Carrillo, Carlos and Dasmohapatra, Sudipta and Jameel, Hasan and Gonzalez, Ronalds}, year={2021}, month={Feb}, pages={19–45} }
 @article{zwilling_jiang_zambrano_venditti_jameel_velev_rojas_gonzalez_2021, title={Understanding lignin micro- and nanoparticle nucleation and growth in aqueous suspensions by solvent fractionation}, volume={23}, ISSN={1463-9262 1463-9270}, url={http://dx.doi.org/10.1039/D0GC03632C}, DOI={10.1039/d0gc03632c}, abstractNote={In recent years, there have been many advances toward developing sustainable, micro- and nanoscale materials from biobased resources such as lignin aimed at strengthening the bioeconomy. It is critical to study the factors affecting nucleation and growth mechanisms, as well as the stability of lignin micro-and nanoparticles (LPs), to further enhance the development of such materials. However, there remains a gap in the literature examining the many interactions present during and after LP formation. These interactions vary with the chemical composition and molecular weight distribution of different kraft lignin (KL) fractions. To examine the composition of different lignin fractions, KL can be fractionated using water-miscible organic solvents of different polarities such as tetrahydrofuran (THF), acetone, and ethanol. Herein, we show that the micro- and nanoparticles formed from each lignin fraction exhibit significant differences in their size (50–300 nm), particle aggregation and fusion propensity, and spherical morphology in aqueous suspensions. These differences are proposed to be a result of the solvent–lignin–water interactions related to molecular weight and functional groups of the lignin fractions and solvent/water polarity. Another factor affecting the nucleation and growth of LPs is the lignin concentration. The LPs formed at low lignin concentrations exhibit a larger average particle size compared to the LPs formed at higher lignin concentrations due to the aggregation and fusion of the small particles. These results will allow for a stronger foundation in understanding the nucleation and growth of LPs when attempting to develop value-added applications for kraft lignin.}, number={2}, journal={Green Chemistry}, publisher={Royal Society of Chemistry (RSC)}, author={Zwilling, Jacob D. and Jiang, Xiao and Zambrano, Franklin and Venditti, Richard A. and Jameel, Hasan and Velev, Orlin D. and Rojas, Orlando J. and Gonzalez, Ronalds}, year={2021}, pages={1001–1012} }
 @article{agate_argyropoulos_jameel_lucia_pal_2020, title={3D Photoinduced Spatiotemporal Resolution of Cellulose-Based Hydrogels for Fabrication of Biomedical Devices}, volume={3}, ISSN={["2576-6422"]}, url={https://doi.org/10.1021/acsabm.0c00517}, DOI={10.1021/acsabm.0c00517}, abstractNote={Rational spatiotemporal irradiation of cellulose-based hydrogels (carboxymethylcellulose (CMC), citric acid, and riboflavin) using a laser diode stereolithography 3D printer obtained architectures referred to as photodegradation addressable hydrogels (PAHs). Under irradiation, these PAHs engage in an unprecedented spatially resolved zonal swelling illustrating marked but controllable changes in swelling and thickness while concomitantly obtaining improved oxygen transmission rate values by 5 times. XPS, carboxyl content, and swelling data comparisons of hydrogel formulations show that photodegradation and ablation of the material occur, where hydroxyl sites of CMC are converted to aldehydes and ketones. XRD data show that the total number of crystalline aggregates in the material are lowered after photoablation. The spatially tuned (photoablated) hydrogel films can thus be shaped into a lens form. The energy required for the lens tuning process can be lowered up to 30 times by incorporation of riboflavin in the films. The method demonstrated here enables the processing of a material that is difficult to be machined or cast by popular contact lens making methods.}, number={8}, journal={ACS APPLIED BIO MATERIALS}, publisher={American Chemical Society (ACS)}, author={Agate, Sachin and Argyropoulos, Dimitris S. and Jameel, Hasan and Lucia, Lucian and Pal, Lokendra}, year={2020}, month={Aug}, pages={5007–5019} }
 @article{jardim_hart_lucia_jameel_chang_2020, title={A Quantitative Comparison of the Precipitation Behavior of Lignin from Sweetgum and Pine Kraft Black Liquors}, volume={15}, ISSN={["1930-2126"]}, DOI={10.15376/biores.15.3.5464-5480}, abstractNote={Lignin is a by-product of the pulp and paper industry that can be precipitated by acidification from black liquor as a potential feedstock for valuable green materials. Precipitation and quantification of lignin from softwood black liquors have been documented and commercialized with well-established methods; however, applying those methods to the precipitation of lignin from hardwood black liquors has produced low lignin yields. A need to understand the main differences between hardwood and softwood lignin precipitation prompted the current investigation. Multiple black liquor samples from sweetgum and pine pulping were obtained at different times of standard kraft cooks. Two lignin fractions were precipitated from each of these black liquors, one at pH 9.5 and one at pH 2.5. Detailed lignin and carbohydrate material balances were performed around each of the sample sets, starting with the wood and ending with precipitated lignin fractions. For all conditions tested, the amount and purity of pine lignin precipitated were superior to sweetgum lignin. The maximum recovery for sweetgum lignin was 69.7%, while for pine lignin, it was 90.9%.}, number={3}, journal={BIORESOURCES}, author={Jardim, Juliana M. and Hart, Peter W. and Lucia, Lucian and Jameel, Hasan and Chang, Houmin}, year={2020}, month={Aug}, pages={5464–5480} }
 @article{assis_pawlak_pal_jameel_reisinger_kavalew_campbell_pawlowska_gonzalez_2020, title={Comparison between uncreped and creped handsheets on tissue paper properties using a creping simulator unit}, volume={27}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-020-03163-0}, number={10}, journal={CELLULOSE}, author={Assis, Tiago and Pawlak, Joel and Pal, Lokendra and Jameel, Hasan and Reisinger, Lee W. and Kavalew, Dale and Campbell, Clayton and Pawlowska, Lucyna and Gonzalez, Ronalds W.}, year={2020}, month={Jul}, pages={5981–5999} }
 @article{sagues_assis_hah_sanchez_johnson_acharya_jameel_park_2020, title={Decarbonizing agriculture through the conversion of animal manure to dietary protein and ammonia fertilizer}, volume={297}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2019.122493}, abstractNote={The decarbonization of agriculture faces many challenges and has received a level of attention insufficient to abate the worst effects of climate change and ensure a sustainable bioeconomy. Agricultural emissions are caused both by fossil-intensive fertilizer use and land-use change, which in turn are driven in part by increasing demand for dietary protein. To address this challenge, we present a synergistic system in which organic waste-derived biogas (a mixture of methane and carbon dioxide) is converted to dietary protein and ammonia fertilizer. This system produces low-carbon fertilizer inputs alongside high-quality protein, addressing the primary drivers of agricultural emissions. If the proposed system were implemented across the United States utilizing readily available organic waste from municipal wastewater, landfills, animal manure, and commercial operations, we estimate 30% of dietary protein intake and 127% of ammonia usage could be displaced while reducing land use, water consumption, and greenhouse gas emissions.}, journal={BIORESOURCE TECHNOLOGY}, publisher={Elsevier BV}, author={Sagues, William J. and Assis, Camilla A. and Hah, Phillip and Sanchez, Daniel L. and Johnson, Zackary and Acharya, Madhav and Jameel, Hasan and Park, Sunkyu}, year={2020}, month={Feb} }
 @article{naithani_tyagi_jameel_lucia_pal_2020, title={Ecofriendly and Innovative Processing of Hemp Hurds Fibers for Tissue and Towel Paper}, volume={15}, ISSN={["1930-2126"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078956694&partnerID=MN8TOARS}, DOI={10.15376/biores.15.1.706-720}, abstractNote={An innovative approach for preparing hemp fibers from hemp hurds for use in tissue and towel grades of paper is described. Hemp hurds are a low value by-product of industrial hemp processing that are generally used for animal bed litter. Tissue paper was fabricated from hemp hurd fibers by following three pulping processes: autohydrolysis (hydrothermal), sodium carbonate-based defibration, and high yield kraft pulping, and benchmarked against hardwood pulp. To meet industrial standards, hardwood and hemp pulp fibers were mixed at a dry mass ratio of 75:25, from which tissue paper sheets were prepared. Desirable tissue paper properties, such as water absorption, burst resistance, softness, and tensile strength (dry and wet), were measured and compared. Characterization of morphological and chemical properties of tissue handsheets was conducted with SEM and time-of-flight-secondary ion mass spectrometry (ToF-SIMS). The combined kraft pulped hardwood and autohydrolyzed hemp pulp fibers displayed improvements in tensile index, burst resistance, and softness of tissue handsheets compared to only kraft hardwood pulp handsheets without adversely impacting water absorption. Hardwood fibers showed a sparse distribution of surface lignin compared to hemp fibers using the same defibration. This technology can lead to a variety of eco-friendly tissue paper products that are not only highly energy efficient, but avoid harsh chemical processing.}, number={1}, journal={BIORESOURCES}, author={Naithani, Ved and Tyagi, Preeti and Jameel, Hasan and Lucia, Lucian A. and Pal, Lokendra}, year={2020}, month={Feb}, pages={706–720} }
 @article{an_li_xue_li_xia_liu_chen_jameel_chang_2020, title={Effect of removing hemicellulose and lignin synchronously under mild conditions on enzymatic hydrolysis of corn stover}, volume={204}, ISSN={0378-3820}, url={http://dx.doi.org/10.1016/j.fuproc.2020.106407}, DOI={10.1016/j.fuproc.2020.106407}, abstractNote={P-toluene sulfonic acid (PTSA) was utilized to pretreat corn stover. Changes in morphology and structure of untreated and pretreated samples were analyzed by ESEM, TEM, BET, XRD and SXT. The characterization results demonstrated that PTSA pretreatment could markedly improve cellulase accessibility to cellulose because of the removal of lignin and hemicellulose simultaneously. The maximum glucose yield (67.2%) with an enzyme loading of 5FPU•g−1 substrate was achieved after the sample was the pretreated at 80 °C for 10 min with 71.0 wt% PTSA. P-toluene sulfonic acid pretreatment was a valid method to improve the enzymatic hydrolysis performance of cellulose in corn stover at low reaction temperature with a short reaction time.}, journal={Fuel Processing Technology}, publisher={Elsevier BV}, author={An, Shengxin and Li, Wenzhi and Xue, Fengyang and Li, Xu and Xia, Ying and Liu, Qiyu and Chen, Liang and Jameel, Hasan and Chang, Hou-min}, year={2020}, month={Jul}, pages={106407} }
 @article{wu_chen_jameel_chang_phillips_jin_2020, title={Effects of Lignin Contents and Delignification Methods on Enzymatic Saccharification of Loblolly Pine}, volume={59}, ISSN={["0888-5885"]}, DOI={10.1021/acs.iecr.0c00645}, abstractNote={Softwood pulp is more recalcitrant toward enzymatic hydrolysis than hardwood or nonwood pulps. Pulps of various kappa numbers were prepared from loblolly pine chips by kraft cooking, which was foll...}, number={18}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Wu, Shufang and Chen, Hui and Jameel, Hasan and Chang, Hou-min and Phillips, Richard and Jin, Yongcan}, year={2020}, month={May}, pages={8532–8537} }
 @article{corbett_knoll_venditti_jameel_park_2020, title={Fiber fractionation to understand the effect of mechanical refining on fiber structure and resulting enzymatic digestibility of biomass}, volume={117}, ISSN={0006-3592 1097-0290}, url={http://dx.doi.org/10.1002/bit.27258}, DOI={10.1002/bit.27258}, abstractNote={Abstract Mechanical refining results in fiber deconstruction and modifications that enhance enzyme accessibility to carbohydrates. Further understanding of the morphological changes occurring to biomass during mechanical refining and the impacts of these changes on enzymatic digestibility is necessary to maximize yields and reduce energy consumption. Although the degree of fiber length reduction relative to fibrillation/delamination can be impacted by manipulating refining variables, mechanical refining of any type (PFI, disk, and valley beater) typically results in both phenomena. Separating the two is not straightforward. In this study, fiber fractionation based on particle size performed after mechanical refining of high‐lignin pulp was utilized to successfully elucidate the relative impact of fibrillation/delamination and fiber cutting phenomena during mechanical refining. Compositional analysis showed that fines contain significantly more lignin than larger size fractions. Enzymatic hydrolysis results indicated that within fractions of uniform fiber length, fibrillation/delamination due to mechanical refining increased enzymatic conversion by 20–30 percentage points. Changes in fiber length had little effect on digestibility for fibers longer than ~0.5 mm. However, the digestibility of the fines fractions was high for all levels of refining even with the high‐lignin content.}, number={4}, journal={Biotechnology and Bioengineering}, publisher={Wiley}, author={Corbett, Derek B. and Knoll, Charlie and Venditti, Richard and Jameel, Hasan and Park, Sunkyu}, year={2020}, month={Jan}, pages={924–932} }
 @article{dou_jiang_li_zhu_liu_lu_zheng_chang_jameel_2020, title={Highly efficient conversion of Kraft lignin into liquid fuels with a Co-Zn-beta zeolite catalyst}, volume={268}, ISSN={["1873-3883"]}, DOI={10.1016/j.apcatb.2019.118429}, abstractNote={Kraft lignin depolymerization to liquid fuels with high yields is crucial to the comprehensive achievement of sustainable and economic feasibility. Herein, we prepared a bimetallic Co-Zn/Off-Al H-beta catalyst through a two-step post synthesis method composed of dealumination and metal incorporation. The bifunctional Co-Zn/Off-Al H-beta catalyst efficiently converted Kraft lignin to liquid fuels, which was attributable to the synergistic effect of Co hydrogen binding sites and Zn Lewis acid sites on H-beta support. Catalytic hydrogenation with Co:Zn = 1:3/Off-Al H-beta catalyst at 320 °C for 24 h gave the highest yield of petroleum ether soluble product (81%, mainly monomers and dimers). Under these conditions, the liquefied lignin gave a higher heating value of 33.3 MJ/kg, which is a significant increase from 26.0 MJ/kg of Kraft lignin. The catalyst stability test showed excellent recyclability. This work provides a paradigm of improving lignin depolymerization efficiency via the combined use of Lewis acid and hydrogenation catalyst.}, journal={APPLIED CATALYSIS B-ENVIRONMENTAL}, author={Dou, Xiaomeng and Jiang, Xiao and Li, Wenzhi and Zhu, Chaofeng and Liu, Qingchuan and Lu, Qiang and Zheng, Xusheng and Chang, Hou-min and Jameel, Hasan}, year={2020}, month={Jul} }
 @misc{jardim_hart_lucia_jameel_2020, title={Insights into the Potential of Hardwood Kraft Lignin to Be a Green Platform Material for Emergence of the Biorefinery}, volume={12}, ISSN={["2073-4360"]}, DOI={10.3390/polym12081795}, abstractNote={Lignin is an abundant, renewable, and relatively cheap biobased feedstock that has potential in energy, chemicals, and materials. Kraft lignin, more specifically, has been used for more than 100 years as a self-sustaining energy feedstock for industry after which it has finally reached more widespread commercial appeal. Unfortunately, hardwood kraft lignin (HWKL) has been neglected over these years when compared to softwood kraft lignin (SWKL). Therefore, the present work summarizes and critically reviews the research and development (R&D) dealing specifically with HWKL. It will also cover methods for HWKL extraction from black liquor, as well as its structure, properties, fractionation, and modification. Finally, it will reveal several interesting opportunities for HWKL that include dispersants, adsorbents, antioxidants, aromatic compounds (chemicals), and additives in briquettes, pellets, hydrogels, carbon fibers and polymer blends and composites. HWKL shows great potential for all these applications, however more R&D is needed to make its utilization economically feasible and reach the levels in the commercial lignin market commensurate with SWKL. The motivation for this critical review is to galvanize further studies, especially increased understandings in the field of HWKL, and hence amplify much greater utilization.}, number={8}, journal={POLYMERS}, author={Jardim, Juliana M. and Hart, Peter W. and Lucia, Lucian and Jameel, Hasan}, year={2020}, month={Aug} }
 @article{jiang_assis_kollman_sun_jameel_chang_gonzalez_2020, title={Lignin fractionation from laboratory to commercialization: chemistry, scalability and techno-economic analysis}, volume={22}, ISSN={["1463-9270"]}, url={https://doi.org/10.1039/D0GC02960B}, DOI={10.1039/d0gc02960b}, abstractNote={A detailed techno-economic analysis on industrial scale lignin fractionation using green solvents.}, number={21}, journal={GREEN CHEMISTRY}, publisher={Royal Society of Chemistry (RSC)}, author={Jiang, Xiao and Assis, Camilla and Kollman, Matthew and Sun, Runkun and Jameel, Hasan and Chang, Hou-min and Gonzalez, Ronalds}, year={2020}, month={Nov}, pages={7448–7459} }
 @article{naithani_lucia_jameel_hart_2020, title={Soybean peroxidase treatment of ultra-high kappa softwood pulp to enhance yield and physical properties}, volume={19}, ISSN={["0734-1415"]}, DOI={10.32964/TJ19.9.437}, abstractNote={The working hypothesis serving as basis for this study is that pulping to a higher kappa number will produce a higher yield pulp, and then treating that pulp with a surface reactive lignin peroxidase to ablate surface lignin will increase specific bonding area. In the present case, the working hypothesis was modified so that soybean peroxidase (SBP) works like lignin peroxidase to modify surface lignin on high-kappa, high-yield softwood pulps to facilitate enhanced fiber-to-fiber bonding such that the resulting paper strength is similar to the lower kappa soft-wood pulp generally used to make linerboard. 
Soybean peroxidase is actually a plant peroxidase that exhibits lignin peroxidase-like activity. It is not a lignin peroxidase derived from white rot fungus. The current work did show a significant improvement in pulp yield (62.2% vs. 55.2% yield for a 103-kappa control linerboard grade sheet), while treatment with SBP showed that tensile, burst, and STFI properties of the pulp were improved, although more convincing data needs to be obtained.}, number={9}, journal={TAPPI JOURNAL}, author={Naithani, Ved and Lucia, Lucian and Jameel, Hasan and Hart, Peter W.}, year={2020}, month={Sep}, pages={437–443} }
 @article{jiang_narron_han_park_chang_jameel_2020, title={Tracing Sweetgum Lignin's Molecular Properties through Biorefinery Processing}, volume={13}, ISSN={["1864-564X"]}, DOI={10.1002/cssc.202001125}, abstractNote={Changes to lignin molecular properties over the course of biorefinery processing was investigated using sweetgum as a feedstock. Hydrothermal pretreatment was used since it is a economically attractive, green process. Three representative biorefinery lignin preparations were obtained with ~70% yield based on raw lignin. The three fractions included soluble lignin adsorbed via resin (XADL), solvent-extracted lignin (HTCELp), and an additional ball-milled residual lignin (HTRELp). By comparing the raw and biorefinery lignin preparations, we have concluded that lignin undergoes both degradation and condensation throughout the various stages of the hydrothermal based biorefinery process. The two fractions made soluble by biorefinery processing, XADL, and HTCELp, were found to be low molecular weight degradation products enriched with free phenolic hydroxyl groups. In addition, about 15% of non-condensed phenolic units were involved in condensation reactions. Quantitative NMR analysis revealed that at least ~28% of b-O-4' substructures were cleaved. Hibbert's ketones were identified in XADL and HTRELp, providing evidence of lignin undergoing acidolysis. The contents of b-5' and b-b' did not change significantly upon biorefinery processing. Finally, episyringaresinol was detected in XADL and HTCELp. It is our hope that these findings will help further demonstrate the specific effects of biorefinery processing upon the lignin in hardwood and facilitate its utilization to improve biorefienery economics.}, number={17}, journal={CHEMSUSCHEM}, author={Jiang, Xiao and Narron, Robert H. and Han, Qiang and Park, Sunkyu and Chang, Hou-min and Jameel, Hasan}, year={2020}, month={Sep}, pages={4613–4623} }
 @article{ribeiro_vaz junior_jameel_chang_narron_jiang_colodette_2019, title={Chemical Study of Kraft Lignin during Alkaline Delignification of E. urophylla x E. grandis Hybrid in Low and High Residual Effective Alkali}, volume={7}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.8b06635}, abstractNote={Chips from E. urophylla x E. grandis hybrid were subjected to kraft cooking using two different approaches: low and high residual effective alkali. The lignin remaining in the pulps were analyzed for hydroxyl and carboxyl functional groups. For both pulping cases, the kappa number varied between 14 and 26. Significant yield gains were observed when kraft cooking was terminated with low residual effective alkali (L-REA) in contrast to those with high residual effective alkali (H-REA) at a given kappa number. The L-REA pulps also tended to contain higher lignin and lower HexA contents than the H-REA pulps at a given kappa number. Cellulolytic enzyme lignin (CEL) was isolated from the studied pulp’s residual lignins, and their hydroxyl functional group distributions were quantified using a method involving ³¹P NMR. Analysis of residual lignins isolated from L-REA and H-REA cooking indicated that L-REA had high contents of phenolic hydroxyl groups and carboxylic acid groups in relation to the H-REA pulps. This work demonstrates the varied lignin chemistry one can expect when residual effective alkali levels are varied during kraft pulping and how this parameter can influence downstream unit operations and overall process performance.}, number={12}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Ribeiro, Robisnea Adriana and Vaz Junior, Silvio and Jameel, Hasan and Chang, Hou-Min and Narron, Robert and Jiang, Xiao and Colodette, Jorge Luiz}, year={2019}, month={Jun}, pages={10274–10282} }
 @article{assi_pawlak_pal_jameel_venditti_reisinger_kavalew_gonzalez_2019, title={Comparison of Wood and Non-Wood Market Pulps for Tissue Paper Application}, volume={14}, ISSN={["1930-2126"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85076457460&partnerID=MN8TOARS}, DOI={10.15376/biores.14.3.6781-6810}, abstractNote={A comparison among ten market pulps at a laboratory scale using uncreped tissue handsheets was performed to study the performance of wood and non-wood pulps for tissue manufacturing, evaluate what fiber features are desired for a specific tissue property, and determine how non-wood pulps can be used to replace or complement wood pulps in tissue products. A characterization of the fiber morphology and handsheet properties (softness, water absorbency, and strength) was performed at different mechanical refining levels. The results showed that the fiber morphology had a major impact on tissue properties. Market pulps with a combination of long fibers, high coarseness, and low fines content can provide superior bulk and water absorbency. Short fibers with thin cell walls and low fines content can impart superior softness. Bleached bamboo soda pulp can replace hardwood and softwood pulps to provide an excellent combination of water absorbency and strength. Bleached bamboo soda pulp can also replace Northern bleached softwood kraft (NBSK) pulp to impart strength without sacrificing softness. Bleached and semi-bleached wheat straw soda pulps presented a similar combination of softness and strength as Southern bleached hardwood kraft (SBHK) pulp. The wheat straw pulps can be used to replace deinked pulp (DIP) pulp to impart intermediate levels of water absorbency and strength.}, number={3}, journal={BIORESOURCES}, author={Assi, Tiago and Pawlak, Joel and Pal, Lokendra and Jameel, Hasan and Venditti, Richard and Reisinger, Lee W. and Kavalew, Dale and Gonzalez, Ronalds W.}, year={2019}, month={Aug}, pages={6781–6810} }
 @misc{londono-zuluaga_jameel_gonzalez_lucia_2019, title={Crustacean shell-based biosorption water remediation platforms: Status and perspectives}, volume={231}, ISSN={["1095-8630"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85057191579&partnerID=MN8TOARS}, DOI={10.1016/j.jenvman.2018.10.096}, abstractNote={The importance of water pollutants on human health has been the subject of intense study and constitutes perhaps the most significant grand challenge for the future of human society. Water remediation faces many challenges in effectively combating pollution, especially for low income populations where poor water sanitation and little to no access to technically competent and cost effective remediation are nearly insurmountable issues. In an effort to provide low-cost adsorbents, research over the last few years has focused on biological residual materials from plants and animal biomass to not only to add value, but to remediate water at a lower cost with the same or improved efficiency as commercially available option. Crustacean shells are among a class of biological residues that are commonly treated as a waste product of the sea food industry. However, potential valorization by remediation of heavy metal ions, organic matter, and anionic species is a topic of high interest in the current eco-friendly environment. The aim of this review is to provide insight on the state of the art of crustacean shells for addressing water remediation and to offer some perspective regarding challenges and the future of this type of biomass.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Londono-Zuluaga, Carolina and Jameel, Hasan and Gonzalez, Ronalds W. and Lucia, Lucian}, year={2019}, month={Feb}, pages={757–762} }
 @article{sagues_park_jameel_sanchez_2019, title={Enhanced carbon dioxide removal from coupled direct air capture-bioenergy systems}, volume={3}, ISSN={["2398-4902"]}, DOI={10.1039/c9se00384c}, abstractNote={Synergistic integration of BECCS and DAC systems decreases costs, increases carbon removal, and extends the impact of scarce biomass resources.}, number={11}, journal={SUSTAINABLE ENERGY & FUELS}, publisher={Royal Society of Chemistry (RSC)}, author={Sagues, William J. and Park, Sunkyu and Jameel, Hasan and Sanchez, Daniel L.}, year={2019}, month={Nov}, pages={3135–3146} }
 @article{gutierrez_royals_jameel_venditti_pal_2019, title={Evaluation of Paper Straws versus Plastic Straws: Development of a Methodology for Testing and Understanding Challenges for Paper Straws}, volume={14}, ISSN={["1930-2126"]}, DOI={10.15376/biores.14.4.8345-8363}, abstractNote={New alternatives to plastic straws are being considered due to consumer demands for sustainability and recent changes in government policies and regulations, such as bans on single-use plastic products. There are concerns regarding paper straw quality and stability over time when in contact with beverages. This study evaluated the performance and properties of commercially available paper straws and their counterpart plastic straws in various intended applications. The physical, mechanical, and compositional characteristics, as well as the liquid interaction properties of the straws, were determined. The paper straws were composed mainly of hardwood fibers that were hard sized with a hydrophobic sizing agent to achieve a contact angle of 102° to 125°. The results indicated that all the evaluated paper straws lost 70% to 90% of their compressive strength after being in contact with the liquid for less than 30 min. Furthermore, the paper straws absorbed liquid at approximately 30% of the straw weight after liquid exposure for 30 min. Increased liquid temperatures caused lower compressive strengths and higher liquid uptake in the paper straws. This report provides directions and methods for testing paper straws and defines current property limitations of paper straws relative to plastic straws.}, number={4}, journal={BIORESOURCES}, author={Gutierrez, Joseph N. and Royals, Aidan W. and Jameel, Hasan and Venditti, Richard A. and Pal, Lokendra}, year={2019}, month={Nov}, pages={8345–8363} }
 @article{jardim_du_hart_lucia_jameel_chang_gracz_2019, title={Fundamental molecular characterization and comparison of the 0, D-0, and E stage effluents from hardwood pulp bleaching}, volume={18}, ISSN={["0734-1415"]}, DOI={10.32964/TJ18.6.341}, abstractNote={The present study characterized effluents from the O, D0, and E stages using nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques to better understand the chemical nature of the dissolved organics formed from the bleaching of a high-yield hardwood kraft pulp. Understanding the structures and molecular weight distribution of these organics is the first step in developing methods to mitigate these contaminates in the discharged effluents. The results indicated that the molecular weight distribution (MWD) of the dissolved organics from oxygen delignification effluent is broader than those from D0 and E stage effluents. In addition, the O stage filtrate contained considerable amounts of lignin and xylan fragments, which showed its efficiency in removing such materials. The effluent from the D0 stage contained a lower amount of high molecular weight fragments and a higher amount of low molecular weight fragments versus the O-stage filtrate. Aromatic structures were nearly absent in the D0 stage filtrate, but the degraded organic material, presumably from oxidized lignin, contained olefinic (C=C) and carbonyl (C=O) functional groups. Furthermore, higher molecular weight fragments were detected in the E-stage effluent, presumably due to the extensive solubilization and removal of the oxidized lignin generated from the D0 pulp.}, number={6}, journal={TAPPI JOURNAL}, author={Jardim, Juliana M. and Du, Xueyu and Hart, Peter W. and Lucia, Lucian and Jameel, Hasan and Chang, Hou-Min and Gracz, Hanna}, year={2019}, month={Jun}, pages={341–351} }
 @article{corbett_hong_venditti_jameel_park_2019, title={Hydrophobic resin treatment of hydrothermal autohydrolysate for prebiotic applications}, volume={9}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/C9RA06018A}, DOI={10.1039/c9ra06018a}, abstractNote={The production of a high-value xylooligosaccharide (XOS) prebiotic product from lignocellulosic autohydrolysate requires processing for the removal of non-carbohydrate components such as lignin and furfural. In this research, the nature of XOS dissolved in autohydrolysate is evaluated including the XOS degree of polymerization (DP) distribution and potential covalent association between XOS and lignin (LCC). The impact of these factors on the yield of XOS during treatment of Miscanthus autohydrolysate with hydrophobic resin is assessed. Over 30% of the XOS in autohydrolysate was found to be likely associated with lignin (“tied” XOS), all of which was removed during hydrophobic resin treatment along with over 90% of the dissolved lignin. However, loss of dissolved XOS during resin treatment was found to not be due solely to XOS association with lignin. Over 50% of the “free,” non-lignin-associated XOS was also removed by resin treatment. Interaction between “free” XOS and the hydrophobic resin was found to be highly dependent on DP with higher DP XOS being removed far more readily than low DP XOS. Over 80% of dissolved “free” XOS with a DP of six and above (X6+) was removed from autohydrolysate during treatment while only 17% of xylose (X1) was removed. Efforts to understand the interaction between the hydrophobic resin and XOS and to improve the recovery of XOS during hydrophobic resin treatment are presented.}, number={55}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Corbett, Derek B. and Hong, Changyoung and Venditti, Richard and Jameel, Hasan and Park, Sunkyu}, year={2019}, pages={31819–31827} }
 @article{huang_sun_chang_yong_jameel_phillips_2019, title={Production of Dissolving Grade Pulp from Tobacco Stalk Through SO2-ethanol-water Fractionation, Alkaline Extraction, and Bleaching Processes}, volume={14}, ISSN={["1930-2126"]}, DOI={10.15376/biores.14.3.5544-5558}, abstractNote={The objective of this study was to evaluate the possibility of producing dissolving grade pulp from tobacco stalk through combining SO2-ethanol-water (SEW) fractionation, alkaline extraction, and bleaching with oxygen (O), chlorine dioxide (D), alkaline extraction with hydrogen peroxide (Ep), and hydrogen peroxide (P) (OD0(Ep)D1P). The results showed that the optimum SEW cooking condition to remove the original xylan and lignin in tobacco stalk to an acceptable level was 6% SO2 charge (by weight) at 135 °C for 180 min. A bleachable pulp (Kappa number of 21.5) was produced from the SEW-treated tobacco stalk via a subsequent 1% NaOH extraction. After the OD0(Ep)D1P sequence bleaching, the bleached pulp showed a high brightness (88.1% ISO) and a high α-cellulose content (94.9%). The viscosity (15.8 cP) and the residual xylan content (4.4%) of the pulp were within acceptable levels for dissolving pulp production. Thus, tobacco stalk was shown to be a viable raw material for dissolving pulp production following a SEW treatment, alkaline extraction, and a conventional bleaching sequence.}, number={3}, journal={BIORESOURCES}, author={Huang, Caoxing and Sun, Runkun and Chang, Hou-min and Yong, Qiang and Jameel, Hasan and Phillips, Richard}, year={2019}, month={Aug}, pages={5544–5558} }
 @article{zhang_jiang_lin_zhao_chang_jameel_2019, title={Reactivity improvement by phenolation of wheat straw lignin isolated from a biorefinery process}, volume={43}, ISSN={["1369-9261"]}, DOI={10.1039/c8nj05016c}, abstractNote={This work describes an effective phenolation process to improve wheat straw biorefinery lignin reactivity.}, number={5}, journal={NEW JOURNAL OF CHEMISTRY}, author={Zhang, Fangda and Jiang, Xiao and Lin, Jian and Zhao, Guangjie and Chang, Hou-min and Jameel, Hasan}, year={2019}, month={Feb}, pages={2238–2246} }
 @article{adebawo_sadeghifar_tilotta_jameel_liu_lucia_2019, title={Spectroscopic Interrogation of the Acetylation Selectivity of Hardwood Biopolymers}, volume={71}, ISSN={["1521-379X"]}, DOI={10.1002/star.201900086}, abstractNote={Acetylation of wood is an age‐old chemical platform known to improve its chemical and physical properties in direct correlation with the degree of acetylation. However, as of yet, no systematic study has been undertaken to probe the selectivity of acetylation of wood. A fundamental understanding of the molecular basis for acetylation of the constituent biopolymers, viz., holocellulose, and lignin for tropical hardwood, an emerging building material, is therefore undertaken. Wood samples are treated with acetic anhydride at 120 °C over a wide range of time periods. The degrees of acetylation and acetyl content of the tropical hardwood are measured to reveal that the acetyl content in which the hydroxyl groups of wood correspond to an increment in weight percent gain as confirmed by FT‐IR for individual wood biopolymers and whole wood. However, surprisingly, ³¹P‐NMR establishes the order of reactivity for the hydroxyl groups as lignin > hemicelluloses > whole wood in direct opposition to their proportions in wood, but in correlation to their direct accessibilities and reactivities.}, number={11-12}, journal={STARCH-STARKE}, author={Adebawo, Funke and Sadeghifar, Hassan and Tilotta, David and Jameel, Hasan and Liu, Yu and Lucia, Lucian}, year={2019}, month={Nov} }
 @article{salem_starkey_pal_lucia_jameel_2019, title={The Topochemistry of Cellulose Nanofibrils as a Function of Mechanical Generation Energy}, volume={8}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/acssuschemeng.9b05806}, DOI={10.1021/acssuschemeng.9b05806}, abstractNote={Nanofibrillated cellulose (NFC) has garnered significant attention as a sustainable biomaterial, but its chemical reactivity with respect to its generation, i.e., fibrillation, has heretofore been unexplored. We prepared NFC samples with varying levels of fibrillation by controlling mechanical energy followed by acetylation as a probe to explore chemical reactivity. The degree of substitution (DS) reached a global maximum after which, surprisingly, it dropped to lower values at higher fibrillation or higher input (generation) energies. This behavior was attributed to two factors: the presence of higher bound water molecules at fibrillated surfaces, which hinder accessibility to cellulose chains, and enhanced self-aggregation of surface hydroxyl groups of NFC due to formation of hydrogen bonds at higher fibrillation. The discovery of these two mitigating factors provides a promising physicochemical strategy for efficient and sustainable production and modification of NFC to optimize performance for different applications.}, number={3}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Salem, Khandoker Samaher and Starkey, Heather R. and Pal, Lokendra and Lucia, Lucian and Jameel, Hasan}, year={2019}, month={Dec}, pages={1471–1478} }
 @article{geng_narron_jiang_pawlak_chang_park_jameel_venditti_2019, title={The influence of lignin content and structure on hemicellulose alkaline extraction for non-wood and hardwood lignocellulosic biomass}, volume={26}, ISSN={0969-0239 1572-882X}, url={http://dx.doi.org/10.1007/s10570-019-02261-y}, DOI={10.1007/s10570-019-02261-y}, number={5}, journal={Cellulose}, publisher={Springer Science and Business Media LLC}, author={Geng, Wenhui and Narron, Robert and Jiang, Xiao and Pawlak, Joel J. and Chang, Hou-min and Park, Sunkyu and Jameel, Hasan and Venditti, Richard A.}, year={2019}, month={Jan}, pages={3219–3230} }
 @article{koo_park_gonzalez_jameel_park_2019, title={Two-stage autohydrolysis and mechanical treatment to maximize sugar recovery from sweet sorghum bagasse}, volume={276}, ISSN={["1873-2976"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85059462040&partnerID=MN8TOARS}, DOI={10.1016/j.biortech.2018.12.112}, abstractNote={Modified autohydrolysis combined with mechanical refining has been suggested to recover free sugars from sweet sorghum bagasse and facilitates enzyme access to cellulose in bagasse for enhancing its conversion to fermentable sugars. The amount of total available sugars in sweet sorghum bagasse was found to be 76.1% and this value was used to evaluate the efficiency of the process suggested. Total sugar recovery was achieved up to 68.1% through the single-stage autohydrolysis at 170 °C for 60 min, followed by mechanical refining and enzymatic hydrolysis; however, the sugar recovery through partial degradation of free sugars induced by high-temperature autohydrolysis was lower than expected. A modified two-stage autohydrolysis was suggested to prevent sugar degradation and the total sugar recovery using this process reached 83.9% of total available sugars in sweet sorghum bagasse.}, journal={BIORESOURCE TECHNOLOGY}, author={Koo, Bonwook and Park, Junyeong and Gonzalez, Ronalds and Jameel, Hasan and Park, Sunkyu}, year={2019}, month={Mar}, pages={140–145} }
 @article{hong_corbett_venditti_jameel_park_2019, title={Xylooligosaccharides as prebiotics from biomass autohydrolyzate}, volume={111}, ISSN={0023-6438}, url={http://dx.doi.org/10.1016/j.lwt.2019.05.098}, DOI={10.1016/j.lwt.2019.05.098}, abstractNote={With an increased awareness of health and wellness, prebiotics have received a great amount of attention recently. In this study, autohydrolyzate from hot water treatment of Miscanthus lignocellulosic biomass was evaluated for its prebiotic effect by fermentation of Lactobacillus brevis strain. The cell growth on raw autohydrolyzate-supplemented media was comparable to the sample grown on glucose until an incubation time of 24 h then gradually declined. Autohydrolyzate contains various inhibitors (25.9% of total dissolved solids) and it was determined that dissolved lignin had a significant inhibitory effect to bacterial growth. When the autohydrolyzate was purified using a hydrophobic resin, purified autohydrolyzate exhibited high bacterial growth (cell density (OD 600) of 4.8) and high acid production (7.7 and 3.1 g/L of lactic and acetic acid, respectively), which was comparable with commercial xylooligosaccharides. In conclusion, mixed oligosaccharides in the autohydrolyzate from Miscanthus have considerable potential as a prebiotic and are comparable with commercial xylooligosaccharides derived products.}, journal={LWT}, publisher={Elsevier BV}, author={Hong, Changyoung and Corbett, Derek and Venditti, Richard and Jameel, Hasan and Park, Sunkyu}, year={2019}, month={Aug}, pages={703–710} }
 @article{he_han_jameel_chang_phillips_wang_2018, title={Comparison of One-Stage Batch and Fed-Batch Enzymatic Hydrolysis of Pretreated Hardwood for the Production of Biosugar}, volume={184}, ISSN={["1559-0291"]}, DOI={10.1007/s12010-017-2633-y}, abstractNote={Fed-batch method has shown a great promise in debottlenecking the high-solid enzymatic hydrolysis for the commercialization of cellulosic biosugar conversion for biofuel/biochemical production. To further improve enzymatic hydrolysis efficiency at high solid loading, fed-batch methods of green liquor-pretreated hardwood were performed to evaluate their effects on sugar recovery by comparing with one-stage batch method in this study. Among all the explored conditions, the fed-batch at 15% consistency gave higher sugar recovery on green liquor-pretreated hardwood compared to that of one-stage batch. By using general linear model analysis, the percentage of enzymatic sugar recovery in fed-batch consistency method (increasing consistency from the initial 10.7 to 15% at intervals of 24 and 48 h) was higher than that of batch hydrolysis at higher density of 15% consistency. Under that best fed-batch condition, the total sugar recovery of pretreated hardwood in enzymatic hydrolysate reached approximately 48.41% at Cellic® enzyme loading of 5 filter-paper unit (FPU)/g and 58.83% at Cellic® enzyme loading of 10 FPU/g with a hydrolysis time of 96 h.}, number={4}, journal={APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY}, author={He, Liang and Han, Qiang and Jameel, Hasan and Chang, Hou-min and Phillips, Richard and Wang, Ziyu}, year={2018}, month={Apr}, pages={1441–1452} }
 @article{corbett_venditti_jameel_park_2018, title={Effect of Mechanical Refining Energy on the Enzymatic Digestibility of Lignocellulosic Biomass}, volume={57}, ISSN={0888-5885 1520-5045}, url={http://dx.doi.org/10.1021/acs.iecr.8b02932}, DOI={10.1021/acs.iecr.8b02932}, abstractNote={Mechanical refining of lignocellulosic biomass has emerged as a promising technology for the improvement of enzymatic hydrolysis yields. Further research is necessary to understand the effects of mechanical refining at different conditions to allow for further optimization of the process. In this research, the impact of refining intensity (specific edge load; kWh/m) is investigated by the use of multiple refining passes to reach equivalent total specific refining energy (SRE) using a 12-in. disk refiner. In addition, the effect of adjusting gap-width vs adjusting consistency to increase refining energy is explored. Results show that enzymatic carbohydrate conversion is a function of SRE, independent of refining intensity. At lower enzyme loadings, gap-width adjustments were observed to be most effective at improving enzymatic digestibility. At higher enzyme loadings carbohydrate conversions leveled-off slightly as SRE increased, implying that there may be an economically optimum degree of refining.}, number={43}, journal={Industrial & Engineering Chemistry Research}, publisher={American Chemical Society (ACS)}, author={Corbett, Derek B. and Venditti, Richard and Jameel, Hasan and Park, Sunkyu}, year={2018}, month={Oct}, pages={14648–14655} }
 @article{liu_chang_jameel_park_2018, title={Furfural production from biomass pretreatment hydrolysate using vapor-releasing reactor system}, volume={252}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/J.BIORTECH.2018.01.006}, DOI={10.1016/J.BIORTECH.2018.01.006}, abstractNote={Biomass hydrolysate from autohydrolysis pretreatment was used for furfural production considering it is in rich of xylose, xylo-oligomers, and other decomposition products from hemicellulose structure. By using the vapor-releasing reactor system, furfural was protected from degradation by separating it from the reaction media. The maximum furfural yield of 73% was achieved at 200 °C for biomass hydrolysate without the use of the catalyst. This is because the presence of organic acids such as acetic acid in hydrolysate functioned as a catalyst. According to the results in this study, biomass hydrolysate with a vapor-releasing system proves to be efficient for furfural production. The biorefinery process which allows the separation of xylose-rich autohydrolysate from other parts from biomass feedstock also improves the overall application of the biomass.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Liu, Lu and Chang, Hou-min and Jameel, Hasan and Park, Sunkyu}, year={2018}, month={Mar}, pages={165–171} }
 @article{tyagi_mathew_opperman_jameel_gonzalez_lucia_hubbe_pal_2018, title={High-Strength Antibacterial Chitosan–Cellulose Nanocrystal Composite Tissue Paper}, volume={35}, ISSN={0743-7463 1520-5827}, url={http://dx.doi.org/10.1021/acs.langmuir.8b02655}, DOI={10.1021/acs.langmuir.8b02655}, abstractNote={A heightened need to control the spread of infectious diseases prompted the current work in which functionalized and innovative antimicrobial tissue paper was developed with a hydrophobic spray-coating of chitosan (Ch) and cellulose nanocrystals (CNCs) composite. It was hypothesized that the hydrophobic nature of chitosan could be counterbalanced by the addition of CNC to maintain fiber formation and water absorbency. Light-weight tissue handsheets were prepared, spray-coated with Ch, CNC, and their composite coating (ChCNC), and tested for antimicrobial activity against Gram-negative bacteria Escherichia coli and a microbial sample from a human hand after using the rest room. Water absorption and strength properties were also analyzed. To activate the surface of cationized tissue paper, an oxygen/helium gas atmospheric plasma treatment was employed on the best performing antimicrobial tissue papers. The highest bactericidal activity was observed with ChCNC-coated tissue paper, inhibiting up to 98% microbial growth. Plasma treatment further improved the antimicrobial activity of the coatings. Water absorption properties were reduced with Ch but increased with CNC. This "self-disinfecting" bactericidal tissue has the potential to be one of the most innovative products for the hygiene industry because it can dry, clean, and resist the infection of surfaces simultaneously, providing significant societal benefits.}, number={1}, journal={Langmuir}, publisher={American Chemical Society (ACS)}, author={Tyagi, Preeti and Mathew, Reny and Opperman, Charles and Jameel, Hasan and Gonzalez, Ronalds and Lucia, Lucian and Hubbe, Martin and Pal, Lokendra}, year={2018}, month={Nov}, pages={104–112} }
 @misc{londono-zuluaga_du_chang_jameel_gonzalez_2018, title={Lignin Modifications and Perspectives towards Applications of Phenolic Foams: A Review}, volume={13}, ISSN={["1930-2126"]}, DOI={10.15376/biores.13.4.Londono-Zuluaga}, abstractNote={Lignin is a complex natural polymer and by-product of the pulp and paper industry. Currently, the increasing interest in bio-based products has motivated the search for alternative renewable feedstocks that can sustainably replace synthetic polymers. Because of the phenolic functionalities of lignin, this natural polymer has attracted interest for application in biomaterials. Among various products, polymeric foams stand out as a potential product in which lignin incorporation has resulted in improved mechanical and thermal properties. This paper reviews the state of lignin foam development, with emphasis placed on phenol-lignin types.}, number={4}, journal={BIORESOURCES}, author={Londono-Zuluaga, Carolina and Du, Jing and Chang, Hou-Min and Jameel, Hasan and Gonzalez, Ronalds}, year={2018}, pages={9158–9179} }
 @article{jiang_liu_du_hu_chang_jameel_2018, title={Phenolation to Improve Lignin Reactivity toward Thermosets Application}, volume={6}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.8b00369}, abstractNote={Phenolation can be used to improve the reactivity and decrease the molecular weight of lignin, thereby making it more useful for various applications. We report an effective phenolation process with only a catalytic amount of sulfuric acid and using phenol as solvent. The optimum phenolation conditions for pine kraft lignin and sweetgum biorefinery lignin were determined to be lignin/phenol (L/P, wt/wt) of 3/5, 5% acid charge at 90 °C for 2 h and L/P of 2/5, 5% acid charge at 110 °C for 2 h, respectively. Phenolation resulted in introducing 30 wt % of phenol onto pine kraft lignin and 60 wt % of phenol onto sweetgum biorefinery lignin and significantly decreasing in the molecular weight of lignin. Phenol was incorporated onto both the side chains and aromatic nuclei of lignin. All lignin substructures of β-O-4′, β-5′/α-O-4′, β–β′, α-carbonyl, etc. were reacted, resulting in a significant decrease in aliphatic hydroxyl groups and increase in the phenolic hydroxyl groups. The comprehensive characterization ...}, number={4}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Jiang, Xiao and Liu, Jie and Du, Xueyu and Hu, Zhoujian and Chang, Hou-min and Jameel, Hasan}, year={2018}, month={Apr}, pages={5504–5512} }
 @article{li_dou_zhu_wang_chang_jameel_li_2018, title={Production of liquefied fuel from depolymerization of kraft lignin over a novel modified nickel/H-beta catalyst}, volume={269}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2018.08.125}, abstractNote={In this study, a novel modified nickel/H-beta (Ni/DeAl-beta) catalyst, which has active acidic sites and hydrogen binding sites, was prepared and used to produce liquefied fuel from lignin. The bifunctional Ni/DeAl-beta catalyst efficiently converted kraft lignin into liquefied fuel due to the synergistic effect of aluminum Lewis acid sites and nickel hydrogen binding sites. At a nickel content of 0.6 mmol/gzeolite, the Ni/DeAl-beta catalyst gave a high liquid product yield of 88.6% at 300 °C for 36 h. Most of the liquid product was dissolved in petroleum ether (73% of 88.6%), which was mainly composed of monomeric and dimeric degradation products. Under these conditions, the higher heating values (HHV) increased from 24.9 MJ/kg for kraft lignin to 32.0 MJ/kg for the liquid product. These results demonstrated the bifunctional Ni/DeAl-beta catalyst could be an efficient catalyst for lignin to liquefied fuel conversion.}, journal={BIORESOURCE TECHNOLOGY}, author={Li, Wenzhi and Dou, Xiaomeng and Zhu, Chaofeng and Wang, Jindong and Chang, Hou-min and Jameel, Hasan and Li, Xiaosen}, year={2018}, month={Dec}, pages={346–354} }
 @article{salam_lucia_jameel_2018, title={Starch Derivatives that Contribute Significantly to the Bonding and Antibacterial Character of Recycled Fibers}, volume={3}, ISSN={["2470-1343"]}, DOI={10.1021/acsomega.8b00307}, abstractNote={The objective of the current research was to fabricate and explore the ability of a renewable resource-based paper strength agent to enhance fiber–fiber bonding and introduce antibacterial properties to recycled fiber paper sheets. The agent corn starch, was modified with diethylenetriamine pentaacetic acid (DTPA), complexed with chitosan, and added to recycled furnishes to provide a plethora of hydrogen bonding sites predicated by acid groups, hydroxyls, and amines. The goal was two-fold: (1) to not only increase interfiber bonding, but (2) afford antibacterial character. The modified corn starch was characterized in previous work by thermal gravimetric analysis, differential scanning calorimeter, and Fourier transform infrared spectroscopy. The recycled pulp slurry was mixed with a ∼1.5% modified starch/chitosan agent before manufacturing a two-dimensional paper substrate that was subjected to mechanical testing. The burst, STFI compressive strength, tensile, and interfiber bonding strength increased 48.8, 49.5, 49.9, and 176%, respectively, while significantly increased gloss was obtained despite slightly diminished tear and roughness. The antibacterial character of these substrates was confirmed by the substrates displaying a 97% bacteria kill rate.}, number={5}, journal={ACS OMEGA}, author={Salam, Abdus and Lucia, Lucian and Jameel, Hasan}, year={2018}, month={May}, pages={5260–5265} }
 @article{assis_greca_ago_balakshin_jameel_gonzalez_rojas_2018, title={Techno-Economic Assessment, Scalability, and Applications of Aerosol Lignin Micro- and Nanoparticles}, volume={6}, ISSN={["2168-0485"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85049954792&partnerID=MN8TOARS}, DOI={10.1021/acssuschemeng.8b02151}, abstractNote={Lignin micro- and nanoparticles (LMNPs) synthesized from side-streams of pulp and paper and biorefinery operations have been proposed for the generation of new, high-value materials. As sustainable alternatives to particles of synthetic or mineral origins, LMNPs viability depends on scale-up, manufacturing cost, and applications. By using experimental data as primary source of information, along with industrial know-how, we analyze dry and spherical LMNPs obtained by our recently reported aerosol/atomization method. First, a preliminary evaluation toward the commercial production of LMNPs from industrial lignin precursors is presented. Following, we introduce potential LMNPs applications from a financial perspective. Mass and energy balances, operating costs, and capital investment are estimated and discussed in view of LMNPs scalability prospects. The main potential market segments identified (from a financial perspective) include composite nanofillers, solid foams, emulsion stabilizers, chelating agents, and UV protection. Our technical, financial, and market assessment represent the basis for R&D planning and efforts to lower the risk related to expected industrialization efforts. Manufacturing costs were estimated between 870 and 1170 USD/t; also, minimum selling prices varied from 1240 and 1560 USD/t, depending on raw materials used. Sensitivity analysis indicated that manufacturing cost can be as low as 600 USD/t, depending on the process conditions considered. Finally, based on the financial assessment, potential applications were identified.}, number={9}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, publisher={American Chemical Society (ACS)}, author={Assis, Camilla Abbati and Greca, Luiz G. and Ago, Mariko and Balakshin, Mikhail Yu. and Jameel, Hasan and Gonzalez, Ronalds and Rojas, Orlando J.}, year={2018}, month={Sep}, pages={11853–11868} }
 @article{reeb_phillips_venditti_treasure_daystar_gonzalez_jameel_kelley_2018, title={Techno‐economic analysis of various biochemical conversion platforms for biosugar production: Trade‐offs of co‐producing biopower versus pellets for either a greenfield, repurpose, or co‐location siting context}, volume={12}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/bbb.1847}, DOI={10.1002/bbb.1847}, abstractNote={In theory, biosugar for conversion to bioproducts can be produced economically from a variety of biomass types in many different technological, co‐production, and biorefinery siting contexts. In this paper, process modeling and financial analysis were conducted for all permutations of biochemical conversion pathways, global biomass types, co‐product options, and biorefinery siting contexts for biosugar production. Minimum sugar revenue (MSR) required to achieve a 15% internal rate of return values for scenarios examined ranged from $150–$748 per tonne. The scenarios with the lowest MSRs were sugarcane in South America and Asia, assuming hot water cook and co‐location or repurpose siting contexts. Another financially optimized scenario is corn grain, also assuming hot water cook, co‐producing distiller’s dry grains and solubles (DDGS), in a repurpose siting context. Against a benchmark sugar price of $408 per metric tonne, an internal rate of return on investment of >15% can typically only be achieved via previously demonstrated conversion pathways using sugar cane and corn grain. Major cost drivers were feedstock cost per metric tonne of carbohydrate, sugar yield, capital investment per annual metric tonne of sugar produced, residue value, and siting context. Near‐term promising technologies include autohydrolysis and dilute acid pathways. Generally, scenarios are financially enhanced by co‐location or repurposing, reducing capital expenditure (CAPEX) by about 33% and 50%, respectively, with negligible impact on cash cost. Conversion process complexity drives capital investment, making some scenarios infeasible despite high sugar yields. Any of the five major cost drivers can impact the order of financial attraction of scenarios, with the outcome of the analysis typically not obvious in advance. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd}, number={3}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Reeb, Carter and Phillips, Richard and Venditti, Richard and Treasure, Trevor and Daystar, Jesse and Gonzalez, Ronalds and Jameel, Hasan and Kelley, Stephen}, year={2018}, month={Feb}, pages={390–411} }
 @article{assis_huang_driemeier_donohoe_kim_kim_gonzalez_jameel_park_2018, title={Toward an understanding of the increase in enzymatic hydrolysis by mechanical refining}, volume={11}, ISSN={["1754-6834"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85055631061&partnerID=MN8TOARS}, DOI={10.1186/s13068-018-1289-3}, abstractNote={Mechanical refining is a low-capital and well-established technology used in pulp and paper industry to improve fiber bonding for product strength. Refining can also be applied in a biorefinery context to overcome the recalcitrance of pretreated biomass by opening up the biomass structure and modifying substrate properties (e.g., morphology, particle size, porosity, crystallinity), which increases enzyme accessibility to substrate and improves carbohydrate conversion. Although several characterization methods have been used to identify the changes in substrate properties, there is no systematic approach to evaluate the extent of fiber cell wall disruption and what physical properties can explain the improvement in enzymatic digestibility when pretreated lignocellulosic biomass is mechanically refined. This is because the fiber cell wall is complex across multiple scales, including the molecular scale, nano- and meso-scale (microfibril), and microscale (tissue level). A combination of advanced characterization tools is used in this study to better understand the effect of mechanical refining on the meso-scale microfibril assembly and the relationship between those meso-scale modifications and enzymatic hydrolysis.Enzymatic conversion of autohydrolysis sugarcane bagasse was improved from 69.6 to 77.2% (11% relative increase) after applying mechanical refining and an increase in enzymatic digestibility is observed with an increase in refining intensity. Based on a combination of advanced characterizations employed in this study, it was found that the refining action caused fiber size reduction, internal delamination, and increase in pores and swellability.A higher level of delamination and higher increase in porosity, analyzed by TEM and DSC, were clearly demonstrated, which explain the faster digestibility rate during the first 72 h of enzymatic hydrolysis for disc-refined samples when compared to the PFI-refined samples. In addition, an increased inter-fibrillar distance between cellulose microfibrils at the nano-meso-scale was also revealed by SFG analysis, while no evidence was found for a change in crystalline structure by XRD and solid-state NMR analysis.}, number={1}, journal={BIOTECHNOLOGY FOR BIOFUELS}, author={Assis, Tiago and Huang, Shixin and Driemeier, Carlos Eduardo and Donohoe, Bryon S. and Kim, Chaehoon and Kim, Seong H. and Gonzalez, Ronalds and Jameel, Hasan and Park, Sunkyu}, year={2018}, month={Oct} }
 @misc{de assis_reisinger_pal_pawlak_jameel_gonzalez_2018, title={Understanding the effect of machine technology and cellulosic fibers on tissue properties - a review}, volume={13}, number={2}, journal={BioResources}, author={De Assis, T. and Reisinger, L. W. and Pal, L. and Pawlak, J. and Jameel, H. and Gonzalez, R. W.}, year={2018} }
 @article{wang_li_wang_chang_jameel_zhang_li_jin_2017, title={A ternary composite oxides S2O82-/ZrO2-TiO2SiO2 as an efficient solid super acid catalyst for depolymerization of lignin}, volume={7}, ISSN={["2046-2069"]}, DOI={10.1039/c7ra09489b}, abstractNote={The solid, super, acid catalyst S2O82−/ZrO2–TiO2–SiO2, which has both a strong Bronsted acid and Lewis acid, was prepared and applied in lignin depolymerization. The results indicate that S2O82−/ZrO2–TiO2–SiO2 is an effective catalyst for lignin depolymerisation since the liquid product was almost completely dissolved in ethyl acetate, indicating that it was comprised of mostly oligomeric lignin degradation products. The effect of hydrogenation co-catalysts (Pd/C, Pt/C and Ru/C, Rh/C) were also studied and found to improve the yield of aromatic compounds and the petroleum ether soluble fraction, which are mostly monomeric and dimeric products. The resulting yields of aromatic compounds and petroleum ether soluble products were 14.8% and 46%, respectively, when S2O82−/ZrO2–TiO2–SiO2 and Pt/C mixed catalyst was used at 310 °C for 24 hours. These results show that the use of a combination Bronsted and Lewis acid catalyst in combination with a hydrogenation catalyst (S2O82−/ZrO2–TiO2–SiO2 together with a noble metal catalyst) opens a practical route for efficient lignin depolymerization.}, number={79}, journal={RSC ADVANCES}, author={Wang, Huizhen and Li, Wenzhi and Wang, Jindong and Chang, Hou-min and Jameel, Hasan and Zhang, Qi and Li, Song and Jin, Lele}, year={2017}, pages={50027–50034} }
 @article{liu_chang_jameel_park_park_2017, title={Catalytic Conversion of Biomass Hydrolysate into 5-Hydroxymethylfurfural}, volume={56}, ISSN={0888-5885 1520-5045}, url={http://dx.doi.org/10.1021/ACS.IECR.7B03635}, DOI={10.1021/ACS.IECR.7B03635}, abstractNote={Biomass hydrolysate, rich in glucose, was used to produce an important platform chemical, 5-hydroxymethylfurfural (HMF). By separating the solid biomass from solution after autohydrolysis, most of the inhibitors were removed from hydrolysate. Biphasic system, which prevents the HMF degradation, was optimized with HCl and AlCl3 catalysts. The yield of HMF conversion using biomass hydrolyzate under the optimized reaction conditions is comparable to the yield using pure glucose as a feedstock. This lab-generated HMF was purified via activated charcoal and oxidized to high value-added chemical, 2,5-furandicarboxylic acid (FDCA). The final FDCA yield of 65% was achieved. The results suggest that, with the separation of nonsugar components such as dissolved lignin and sugar degradation products, biomass hydrolysate is a promising source for HMF and FDCA production.}, number={49}, journal={Industrial & Engineering Chemistry Research}, publisher={American Chemical Society (ACS)}, author={Liu, Lu and Chang, Hou-min and Jameel, Hasan and Park, Ji-Yeon and Park, Sunkyu}, year={2017}, month={Nov}, pages={14447–14453} }
 @article{assis_houtman_phillips_bilek_rojas_pal_peresin_jameel_gonzalez_2017, title={Conversion Economics of Forest Biomaterials: Risk and Financial Analysis of CNC Manufacturing}, volume={11}, ISSN={["1932-1031"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85020653487&partnerID=MN8TOARS}, DOI={10.1002/bbb.1782}, abstractNote={Commercialization of cellulose nanocrystals (CNC) presents opportunities for a wide range of new products. Techno‐economic assessments can provide insightful information for the efficient design of conversion processes, drive cost‐saving efforts, and reduce financial risks. In this study, we conducted techno‐economic assessments for CNC production using information from the USDA Forest Products Laboratory Pilot Plant, literature, and discussions with experts. Scenarios considered included variations related to greenfield, co‐location, and acid recovery. Operating costs, capital investment, minimum product selling price (MPSP), financial performance metrics, and the effect of drying and higher reaction yields on CNC manufacturing financials were estimated for each scenario. The lowest MPSP was found for the co‐location without acid recovery scenario, mainly driven by capital investment. Risk analysis indicates 95% probability of manufacturing costs lower than USD 5900/t of CNC (dry equivalent) and a MPSP lower than USD 7200/t of CNC (dry equivalent). Finally, based on our analysis, we provide guidance on process optimizations that can improve the economic performance of CNC manufacturing process. In addition, a risk profile of the CNC manufacturing business is provided. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd}, number={4}, journal={BIOFUELS BIOPRODUCTS & BIOREFINING-BIOFPR}, publisher={Wiley}, author={Assis, Camilla Abbati and Houtman, Carl and Phillips, Richard and Bilek, E. M. and Rojas, Orlando J. and Pal, Lokendra and Peresin, Maria Soledad and Jameel, Hasan and Gonzalez, Ronalds}, year={2017}, pages={682–700} }
 @article{huang_he_chang_jameel_yong_2017, title={Coproduction of Ethanol and Lignosulfonate From Moso Bamboo Residues by Fermentation and Sulfomethylation}, volume={8}, ISSN={["1877-265X"]}, DOI={10.1007/s12649-016-9629-7}, number={3}, journal={WASTE AND BIOMASS VALORIZATION}, author={Huang, Caoxing and He, Juan and Chang, Hou-min and Jameel, Hasan and Yong, Qiang}, year={2017}, month={Apr}, pages={965–974} }
 @article{de assis_houtman_phillips_bilek_rojas_pal_peresin_jameel_gonzalez_2017, title={Cover Image, Volume 11, Issue 4}, volume={11}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/BBB.1798}, DOI={10.1002/BBB.1798}, abstractNote={The cover image, by Camilla Abbati de Assis et al., is based on the Modeling and Analysis Conversion Economics of Forest Biomaterials: Risk and Financial Analysis of CNC Manufacturing , DOI: 10.1002/bbb.1782 . image}, number={4}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={de Assis, Camilla Abbati and Houtman, Carl and Phillips, Richard and Bilek, E.M. (Ted) and Rojas, Orlando J. and Pal, Lokendra and Peresin, Maria Soledad and Jameel, Hasan and Gonzalez, Ronalds}, year={2017}, month={Jul}, pages={i-i} }
 @article{silva_jameel_borges gomes_ribas batalha_coura_colodette_2017, title={Effect of Lignin Carbohydrate Complexes of Hardwood Hybrids on the Kraft Pulping Process}, volume={37}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2016.1235584}, abstractNote={Lignin-carbohydrates complexes influence many chemical properties in the wood, such as difficult-to-remove lignin from Kraft pulps at the end of pulping due to the occurrence of lignin carbohydrates bonds. Therefore, this study aimed to study the influence of lignin-carbohydrate complexes on eucalyptus Kraft pulping. Spectroscopic techniques (13C NMR and HSQC-2D) were applied for the determination and quantification of lignin-carbohydrate complex (LCC) structures, and then evaluated the effect of LCC on Kraft pulping of eucalyptus hybrids. The analytical tools allowed the identification and quantification of the benzyl ether, γ-ester, and phenyl glucoside linkages of the lignin-carbohydrate complexes in eucalyptus hybrid wood. The glycosidic phenyl and γ-ester linkages are, respectively, more and less significant from the quantitative point of view. Analysis of 13C NMR of the samples showed that the eucalyptus hybrid GxGL contained high β-O-4 linkages content and also higher pulping yield than the other samples, suggesting that the linkages between lignin are more important than LCC linkages in pulping.}, number={1}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Silva, Vanessa Lopes and Jameel, Hasan and Borges Gomes, Fernando Jose and Ribas Batalha, Larisse Aparecida and Coura, Marcela Ribeiro and Colodette, Jorge Luiz}, year={2017}, pages={52–61} }
 @article{ren_meng_chang_kelley_jameel_park_2017, title={Effect of blending ratio of loblolly pine wood and bark on the properties of pyrolysis bio-oils}, volume={167}, ISSN={["1873-7188"]}, DOI={10.1016/j.fuproc.2017.06.025}, abstractNote={Bark, which is available in abundance, has recently become a topic of interest when considering alternative materials for the production of pyrolysis bio-oil. Previous studies have revealed that the pyrolysis behavior of bark differs remarkably from that of wood in that bark typically generates a phase-separated bio-oil. In this study, blends of loblolly pine wood and bark were pyrolyzed to investigate the effect of blending ratio on the yield and properties of derived bio-oils. Trends of lower decomposition rate, decreased organic yield, and increased bio-char yield were observed as bark percentage in the feedstock increased, while the amount of levoglucosan in bio-oil increased. Pyrolysis reactivity, which includes yield and physical properties of the bio-oil, was found to have a linear relationship with the blending ratio of pine bark. It was found that blending up to 50% bark in the feedstock still produced a homogeneous bio-oil.}, journal={FUEL PROCESSING TECHNOLOGY}, author={Ren, Xueyong and Meng, Jiajia and Chang, Jianmin and Kelley, Stephen S. and Jameel, Hasan and Park, Sunkyu}, year={2017}, month={Dec}, pages={43–49} }
 @article{li_zhu_lu_liu_guan_chang_jameel_ma_2017, title={Enhanced furfural production from raw corn stover employing a novel heterogeneous acid catalyst}, volume={245}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2017.08.077}, abstractNote={With the aim to enhance the direct conversion of raw corn stover into furfural, a promising approach was proposed employing a novel heterogeneous strong acid catalyst (SC-CaCt-700) in different solvents. The novel catalyst was characterized by elemental analysis, N2 adsorption-desorption, FT-IR, XPS, TEM and SEM. The developed catalytic system demonstrated superior efficacy for furfural production from raw corn stover. The effects of reaction temperature, residence time, catalyst loading, substrate concentration and solvent were investigated and optimized. 93% furfural yield was obtained from 150 mg corn stover at 200 °C in 100 min using 45 mg catalyst in γ-valerolactone (GVL). In comparison, 51.5% furfural yield was achieved in aqueous media under the same conditions (200 °C, 5 h, and 45 mg catalyst), which is of great industrial interest. Furfural was obtained from both hemicelluloses and cellulose in corn stover, which demonstrated a promising routine to make the full use of biomass.}, journal={BIORESOURCE TECHNOLOGY}, author={Li, Wenzhi and Zhu, Yuanshuai and Lu, Yijuan and Liu, Qiyu and Guan, Shennan and Chang, Hou-min and Jameel, Hasan and Ma, Longlong}, year={2017}, month={Dec}, pages={258–265} }
 @article{xiang_sen_min_savithri_lu_jameel_chiang_chang_2017, title={Field-Grown Transgenic Hybrid Poplar with Modified Lignin Biosynthesis to Improve Enzymatic Saccharification Efficiency}, volume={5}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.6b02740}, abstractNote={Hybrid poplars (Populus nigra L. × Populus maximowiczii A.) were genetically modified through antisense insertion of the 4-coumarate:coenzyme A ligase (4CL) gene. Compositional changes in response to this genetic change were measured in the field after 2 and 3 years of growth. The stem samples were treated with either green liquor or dilute acid pretreatments, representing alkaline and acid pretreatments. The enzymatic saccharification of the untreated and pretreated transgenic poplars were evaluated. After transgenic species were transplanted into the environment, they showed reduced recalcitrance to chemicals (i.e., pretreatments) and enzymes despite their lignin content and S/V ratio being comparable to those of the wild types. Compared to the field-grown poplars, the sugar yield increased up to 103% for untreated transgenic samples and increased 22% for acid- and green liquor-pretreated transgenic samples. This shows that field-grown transgenic hybrid poplars with modified lignin biosynthesis have imp...}, number={3}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Xiang, Zhouyang and Sen, Suman Kumar and Min, Douyong and Savithri, Dhanalekshmi and Lu, Fachuang and Jameel, Hasan and Chiang, Vincent and Chang, Hou-min}, year={2017}, month={Mar}, pages={2407–2414} }
 @article{jiang_savithri_du_pawar_jameel_chang_zhou_2017, title={Fractionation and Characterization of Kraft Lignin by Sequential Precipitation with Various Organic Solvents}, volume={5}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.6b02174}, abstractNote={The value-added utilizations of technical lignin are restricted by its heterogeneous features, such as high polydispersity, complex functional group distribution, ununiformed reactivity, etc. Fractionation of lignin into more homogeneous parts represents a promising approach to overcome this challenge. In the present study, softwood kraft lignin was fractionated into four different portions (F1, F2, F3, and F4) by first dissolving it in a methanol–acetone mixture followed by sequential precipitation with various organic solvents (ethyl acetate, 1:1 ethyl acetate/petroleum ether, petroleum ether) of decreasing solubility parameters. The yields of various fractions F1, F2, F3, and F4 were 48%, 39%, 10%, and 3%, respectively. The results from gel permeation chromatography indicated that the molecular weights of each fraction decreased from F1 to F4. The lowest molecular weight fraction F4 contained mainly monomeric and dimeric aromatic structures such as guaiacol and vanillin formed from lignin degradation. ...}, number={1}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Jiang, Xiao and Savithri, Dhanalekshmi and Du, Xueyu and Pawar, Siddhesh and Jameel, Hasan and Chang, Hou-Min and Zhou, Xiaofan}, year={2017}, month={Jan}, pages={835–842} }
 @article{li_li_lu_jameel_chang_ma_2017, title={High conversion of glucose to 5-hydroxymethylfurfural using hydrochloric acid as a catalyst and sodium chloride as a promoter in a water/gamma-valerolactone system}, volume={7}, ISSN={["2046-2069"]}, DOI={10.1039/c7ra00701a}, abstractNote={Biomass derived 5-hydroxymethylfurfural (HMF) is regarded as an important platform molecule for the synthesis of value-added chemicals and fuels, but the high production cost has always been a bottleneck for the industrial scale use of HMF. Different mineral acids (HCl and H2SO4) being used as the catalyst and different salts being used as the reaction promoter were evaluated. It was found that HCl, in combination with NaCl, in a water/γ-valerolactone system showed high selectivity and impressive efficiency for the synthesis of HMF from glucose. The optimal conditions to obtain the best HMF yield (62.45%) were 0.2 M HCl and 0.1 M NaCl at 140 °C with a residence time of 60 minutes. An 18.22% molar yield of LA was obtained as a by-product. The effect of different anions was also investigated, and it was determined that not only the hydrogen ions, but also the nature of the acid and the type of salt played a joint role in improving the HMF yield. In addition, a possible synthesis pathway was proposed for large scale production of HMF.}, number={24}, journal={RSC ADVANCES}, author={Li, Minghao and Li, Wenzhi and Lu, Yijuan and Jameel, Hasan and Chang, Hou-min and Ma, Longlong}, year={2017}, pages={14330–14336} }
 @article{narron_han_park_chang_jameel_2017, title={Lignocentric analysis of a carbohydrate-producing lignocellulosic biorefinery process}, volume={241}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2017.05.207}, abstractNote={A biologically-based lignocellulosic biorefinery process for obtaining carbohydrates from raw biomass was investigated across six diverse biomasses (three hardwoods & three nonwoods) for the purpose of decoding lignin's influence on sugar production. Acknowledging that lignin could positively alter the economics of an entire process if valorized appropriately, we sought to correlate the chemical properties of lignin within the process to the traditional metrics associated with carbohydrate production-cellulolytic digestibility and total sugar recovery. Based on raw carbohydrate, enzymatic recovery ranged from 40 to 64% w/w and total recovery ranged from 70 to 87% w/w. Using nitrobenzene oxidation to quantify non-condensed lignin structures, it was found that raw hardwoods bearing increasing non-condensed S/V ratios (2.5-5.1) render increasing total carbohydrate recovery from hardwood biomasses. This finding indicates that the chemical structure of hardwood lignin influences the investigated biorefinery process' ability to generate carbohydrates from a given raw hardwood feedstock.}, journal={BIORESOURCE TECHNOLOGY}, author={Narron, Robert H. and Han, Qiang and Park, Sunkyu and Chang, Hou-min and Jameel, Hasan}, year={2017}, month={Oct}, pages={857–867} }
 @article{wang_li_wang_ma_li_chang_jameel_2017, title={Liquefaction of kraft lignin by hydrocracking with simultaneous use of a novel dual acid-base catalyst and a hydrogenation catalyst}, volume={243}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2017.06.024}, abstractNote={In this study, a novel catalyst, S2O82−-KNO3/TiO2, which has active acidic and basic sites, was prepared and used in lignin hydrocracking with a co-catalyst, Ru/C. Ru/C is an efficient hydrogenation catalyst and S2O82−-KNO3/TiO2 is a dual catalyst, which could efficiently degrade lignin. This catalytic hydrogenation system can reduce solid products to less than 1%, while giving a high liquid product yield of 93%. Catalytic hydrocracking of kraft lignin at 320 °C for 6 h gave 93% liquid product with 0.5% solid product. Most of this liquid product was soluble in petroleum ether (60% of 93%), which is a clear liquid and comprises mainly of monomeric and dimeric degradation products. These results demonstrated that the combination of the two catalysts is an efficient catalyst for liquefaction of lignin, with little char formation (∼1%). This concept has the potential to produce valuable chemicals and fuels from lignin under moderate conditions.}, journal={BIORESOURCE TECHNOLOGY}, author={Wang, Jindong and Li, Wenzhi and Wang, Huizhen and Ma, Qiaozhi and Li, Song and Chang, Hou-min and Jameel, Hasan}, year={2017}, month={Nov}, pages={100–106} }
 @article{jones_venditti_park_jameel_2017, title={Optimization of Pilot Scale Mechanical Disk Refining for Improvements in Enzymatic Digestibility of Pretreated Hardwood Lignocellulosics}, volume={12}, ISSN={1930-2126}, url={http://dx.doi.org/10.15376/biores.12.3.4567-4593}, DOI={10.15376/biores.12.3.4567-4593}, abstractNote={Mechanical refining has potential application for overcoming lignocellulosic biomass recalcitrance to enzyme hydrolysis and improving biomass digestibility. This study highlighted the ability for a pilot scale disc refiner to improve the total carbohydrate conversion to sugars from 39% (unrefined hardwood sodium carbonate biomass) to 90% (0.13 mm gap, 20% consistency, ambient temperature) by optimizing the refining variables. The different biomass properties that changed with refining indicated the expected increase in sugar conversion. Controlling the refining parameters to narrower gaps and higher consistencies increased the resulting refined biomass hydrolysis. Positive correlations that increases in net specific energy (NSE) input and refining intensity (SEL) improved the enzymatic hydrolysis. In some severe cases, over-refining occurred when smaller gaps, higher consistencies, and more energy input reached a point of diminished return. The energy input in these scenarios, however, was much greater than realistically feasible for industrial application. Although well-established in the pulp and paper industry, gaps in understanding the fundamentals of refining remain. The observations and results herein provide the justification and opportunity for further mechanical refining optimization to maximize and adapt the mechanical refining technology for maximum efficiency within the process of biochemical conversion to sugar.}, number={3}, journal={BioResources}, publisher={BioResources}, author={Jones, Brandon W. and Venditti, Richard and Park, Sunkyu and Jameel, Hasan}, year={2017}, month={May}, pages={4567–4593} }
 @article{zhu_li_lu_zhang_jameel_chang_ma_2017, title={Production of furfural from xylose and corn stover catalyzed by a novel porous carbon solid acid in gamma-valerolactone}, volume={7}, ISSN={["2046-2069"]}, DOI={10.1039/c7ra03995f}, abstractNote={A resorcinol-formaldehyde resin carbon (RFC) catalyst with a well-developed, ordered, mesoporous framework was prepared using a soft template method at room temperature. The carbon was sulfonated in water using sulfanilic acid under mild atmospheric conditions. The sulfonated RFC (S-RFC) was characterized by N2 adsorption–desorption, elemental analysis, TEM, XPS, and FT-IR. It was determined that S-RFC is an efficient solid acid catalyst for furfural production from xylose and corn stover in γ-valerolactone (GVL). The effects of reaction time, reaction temperature, catalyst loading, substrate dosage and water concentration were investigated. 80% furfural yield and 100% xylose conversion were obtained from xylose at 170 °C in 15 min with 0.5 g catalyst. Comparatively, 68.6% furfural yield was achieved from corn stover at 200 °C in 100 min when using 0.6 g catalyst. Since there was no discernable decrease in furfural yield after multiple conversions utilizing the same catalyst, the recyclability of the catalyst is considered good.}, number={48}, journal={RSC ADVANCES}, author={Zhu, Yuanshuai and Li, Wenzhi and Lu, Yijuan and Zhang, Tingwei and Jameel, Hasan and Chang, Hou-min and Ma, Longlong}, year={2017}, pages={29916–29924} }
 @article{assis_gonzalez_kelley_jameel_bilek_daystar_handfield_golden_prestemon_singh_et al._2017, title={Risk management consideration in the bioeconomy}, volume={11}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/bbb.1765}, DOI={10.1002/bbb.1765}, abstractNote={In investing in a new venture, companies aim to increase their competitiveness and generate value in scenarios where volatile markets, geopolitical instabilities, and disruptive technologies create uncertainty and risk. The biobased industry poses additional challenges as it competes in a mature, highly efficient market, dominated by petroleum‐based companies, and faces significant feedstock availability and variability constraints, limited technological data, and uncertain market conditions for newly developed products. Thus, decision‐making strategies and processes for these investment projects must consider solid risk estimation and mitigation measures. Focusing on the biobased industrial sector, this paper critically reviews state‐of‐the‐art probabilistic and deterministic methodologies for assessing financial risk; discusses how a complete risk analysis should be performed; and addresses risk management, listing major risks and possible mitigation strategies. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd}, number={3}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Assis, C. A. and Gonzalez, R. and Kelley, S. and Jameel, H. and Bilek, T. and Daystar, J. and Handfield, R. and Golden, J. and Prestemon, J. and Singh, D. and et al.}, year={2017}, month={Apr}, pages={549–566} }
 @article{fritz_salas_jameel_rojas_2017, title={Self-association and aggregation of kraft lignins via electrolyte and nonionic surfactant regulation: stabilization of lignin particles and effects on filtration}, volume={32}, number={4}, journal={Nordic Pulp & Paper Research Journal}, author={Fritz, C. and Salas, C. and Jameel, H. and Rojas, O. J.}, year={2017}, pages={572–585} }
 @article{narron_chang_jameel_park_2017, title={Soluble Lignin Recovered from Biorefinery Pretreatment Hydrolyzate Characterized by Lignin-Carbohydrate Complexes}, volume={5}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.7b02716}, abstractNote={The lignin rendered soluble by lignocellulosic biorefinery pretreatment remains insufficiently understood along the lines of molecular properties and chemical composition. To procure a representative soluble lignin preparation, an aromatic-selective adsorptive resin was utilized. Approximately 90% of soluble lignin could be recovered from autohydrolysis pretreatment hydrolyzate (autohydrolyzate) produced from a hardwood and a nonwood biomass. Adsorbate compositional characterization revealed a befuddling magnitude of carbohydrate in selectively isolated lignin adsorbates. Quantitative structural analysis of the lignin by NMR suggested lignin–carbohydrate complexes (LCCs) as the cause behind the pronounced carbohydrate contents. Analyzed spectra revealed both hardwood and nonwood soluble lignin features of ∼10 total LCC per 100 aromatic rings, with each lignin bearing unique LCC profiles. In addition, native structures remained in large quantities. The improved understanding of hydrolyzate-soluble lignin g...}, number={11}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Narron, Robert H. and Chang, Hou-min and Jameel, Hasan and Park, Sunkyu}, year={2017}, month={Nov}, pages={10763–10771} }
 @article{li_zhang_xin_su_ma_jameel_chang_pei_2017, title={p-Hydroxybenzenesulfonic acid–formaldehyde solid acid resin for the conversion of fructose and glucose to 5-hydroxymethylfurfural}, volume={7}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/C7RA03155F}, DOI={10.1039/C7RA03155F}, abstractNote={A novel solid p-hydroxybenzenesulfonic acid–formaldehyde resin (SPFR) was prepared via a straightforward hydrothermal method. The catalytic properties of SPFR solid acids were evaluated in the dehydration reaction of fructose and glucose to 5-hydroxymethylfurfural (HMF). SEM, TEM, N2 adsorption–desorption, elemental analysis (EA), thermogravimetric analysis (TGA), and FT-IR were used to explore the effects of catalyst structure and composition on the HMF preparation from fructose. The effects of reaction time and temperature on the dehydration of fructose and glucose were also investigated. An HMF yield as high as 82.6% was achieved from fructose at 140 °C after 30 min, and 33.0% was achieved from glucose at 190 °C in 30 min. Furthermore, the recyclability of SPFR for the HMF production from fructose in 5 cycles was good.}, number={44}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Li, Wenzhi and Zhang, Tingwei and Xin, Haosheng and Su, Mingxue and Ma, Longlong and Jameel, Hason and Chang, Hou-min and Pei, Gang}, year={2017}, pages={27682–27688} }
 @article{li_li_liu_jameel_chang_an_ma_2016, title={A Two-Step Conversion of Corn Stover into Furfural and Levulinic Acid in a Water/Gamma-Valerolactone System}, volume={11}, ISSN={["1930-2126"]}, DOI={10.15376/biores.11.4.8239-8256}, abstractNote={A two-step hydrolysis method was evaluated as a potential means of obtaining high yields of furfural and levulinic acid from corn stover using sulfuric acid as catalyst in a water/gamma-valerolactone (GVL) system. The corn stover underwent a high-temperature hydrolysis process to produce levulinic acid, followed by a low-temperature hydrolysis process to produce furfural. A series of experiments were conducted to explore the relationship between the different reaction parameters and the final yields of furfural and levulinic acid. Scanning electron microscopy (SEM) pictures together with X-ray diffraction (XRD) analysis were used to further elaborate on the hydrolysis results. Molar yields of about 70.65% furfural and 57.7% levulinic acid were obtained by applying this method with a low temperature of 140 °C and a high temperature of 190 °C, together with 0.2 M of sulfuric acid used as the catalyst. These results indicated that this was an effective way to obtain satisfactory yields of furfural and levulinic acid from corn stover.}, number={4}, journal={BIORESOURCES}, author={Li, Minghao and Li, Wenzhi and Liu, Qiyu and Jameel, Hasan and Chang, Hou-min and An, Shengxin and Ma, Longlong}, year={2016}, month={Nov}, pages={8239–8256} }
 @article{li_liu_ma_zhang_ma_jameel_chang_2016, title={A two-stage pretreatment process using dilute hydrochloric acid followed by Fenton oxidation to improve sugar recovery from corn stover}, volume={219}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2016.08.025}, abstractNote={A two-stage pretreatment process is proposed in this research in order to improve sugar recovery from corn stover. In the proposed process, corn stover is hydrolyzed by dilute hydrochloric acid to recover xylose, which is followed by a Fenton reagent oxidation to remove lignin. 0.7wt% dilute hydrochloric acid is applied in the first stage pretreatment at 120°C for 40min, resulting in 81.0% xylose removal. Fenton reagent oxidation (1g/L FeSO4·7H2O and 30g/L H2O2) is performed at room temperature (about 20°C) for 12 has a second stage which resulted in 32.9% lignin removal. The glucose yield in the subsequent enzymatic hydrolysis was 71.3% with a very low cellulase dosage (3FPU/g). This two-stage pretreatment is effective due to the hydrolysis of hemicelluloses in the first stage and the removal of lignin in the second stage, resulting in a very high sugar recovery with a low enzyme loading.}, journal={BIORESOURCE TECHNOLOGY}, author={Li, Wenzhi and Liu, Qiyu and Ma, Qiaozhi and Zhang, Tingwei and Ma, Longlong and Jameel, Hasan and Chang, Hou-min}, year={2016}, month={Nov}, pages={753–756} }
 @misc{narron_kim_chang_jameel_park_2016, title={Biomass pretreatments capable of enabling lignin valorization in a biorefinery process}, volume={38}, ISSN={["1879-0429"]}, DOI={10.1016/j.copbio.2015.12.018}, abstractNote={Recent techno-economic studies of proposed lignocellulosic biorefineries have concluded that creating value from lignin will assist realization of biomass utilization into valuable fuels, chemicals, and materials due to co-valorization and the new revenues beyond carbohydrates. The pretreatment step within a biorefinery process is essential for recovering carbohydrates, but different techniques and intensities have a variety of effects on lignin. Acidic and alkaline pretreatments have been shown to produce diverse lignins based on delignification chemistry. The valorization potential of pretreated lignin is affected by its chemical structure, which is known to degrade, including inter-lignin condensation under high-severity pretreatment. Co-valorization of lignin and carbohydrates will require dampening of pretreatment intensities to avoid such effects, in spite of tradeoffs in carbohydrate production.}, journal={CURRENT OPINION IN BIOTECHNOLOGY}, author={Narron, Robert H. and Kim, Hoyong and Chang, Hou-min and Jameel, Hasan and Park, Sunkyu}, year={2016}, month={Apr}, pages={39–46} }
 @article{li_xu_zhang_li_jameel_chang_ma_2016, title={Catalytic Conversion of Biomass-derived Carbohydrates into 5-Hydroxymethylfurfural using a Strong Solid Acid Catalyst in Aqueous gamma-Valerolactone}, volume={11}, ISSN={["1930-2126"]}, DOI={10.15376/biores.11.3.5839-5853}, abstractNote={Selective conversion of biomass-derived carbohydrates into 5-hydroxy-methylfurfural (HMF) is of great significance for biomass conversion. In this study, a novel solid Bronsted acid was prepared simply by the copolymerization of paraformaldehyde and p-toluenesulfonic acid and then used to catalyze the conversion of various carbohydrates into HMF in γ-valerolactone-water (GVL/H2O) reaction medium for the first time. The catalyst exhibited strong acidity, good water resistance, and high thermal stability. The present work focuses on the effects of various reaction parameters, including reaction temperature, time, water concentration, solvent, fructose level, and catalyst loading, on fructose dehydration. The catalyst exhibited excellent catalytic performance for HMF production from fructose in GVL and furnished a high HMF yield of 78.1% at 130 °C in 30 min. The recycling experiments suggested that the solid acid catalyst could be recycled at least seven times without a noticeable decrease in the catalytic activity. In addition, an attempt to study the one-step conversion of sucrose, glucose, and cellulose into HMF and furfural was performed using the same catalytic system.}, number={3}, journal={BIORESOURCES}, author={Li, Wenzhi and Xu, Zhiping and Zhang, Tingwei and Li, Guojun and Jameel, Hasan and Chang, Hou-min and Ma, Longlong}, year={2016}, month={Aug}, pages={5839–5853} }
 @article{zhang_li_xu_liu_ma_jameel_chang_ma_2016, title={Catalytic conversion of xylose and corn stalk into furfural over carbon solid acid catalyst in gamma-valerolactone}, volume={209}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2016.02.108}, abstractNote={A novel carbon solid acid catalyst was synthesized by the sulfonation of carbonaceous material which was prepared by carbonization of sucrose using 4-BDS as a sulfonating agent. TEM, N2 adsorption–desorption, elemental analysis, XPS and FT-IR were used to characterize the catalyst. Then, the catalyst was applied for the conversion of xylose and corn stalk into furfural in GVL. The influence of the reaction time, temperature and dosage of catalyst on xylose dehydration were also investigated. The Brønsted acid catalyst exhibited high activity in the dehydration of xylose, with a high furfural yield of 78.5% at 170 °C in 30 min. What’s more, a 60.6% furfural yield from corn stalk was achieved in 100 min at 200 °C. The recyclability of the sulfonated carbon catalyst was perfect, and it could be reused for 5 times without the loss of furfural yields.}, journal={BIORESOURCE TECHNOLOGY}, author={Zhang, Tingwei and Li, Wenzhi and Xu, Zhiping and Liu, Qiyu and Ma, Qiaozhi and Jameel, Hasan and Chang, Hou-min and Ma, Longlong}, year={2016}, month={Jun}, pages={108–114} }
 @article{du_li_xu_wu_jameel_chang_ma_2016, title={Characterization Of C-60/Bi2TiO4F2 as a Potential Visible Spectrum Photocatalyst for The Depolymerization of Lignin}, volume={36}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2016.1173063}, abstractNote={Effects of a photocatalyst, C60-modified Bi2TiO4F2, on pine kraft lignin under visible light irradiation were investigated, along with those of Bi2TiO4F2 and C60/TiO2 as references. The influences of pH, C60 mass fraction, and the initial lignin concentration on lignin conversion and yields of mono-phenolic products were investigated. Seven products were determined by GC/MS, including phenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, vanillin, acetovanillone, and homovanillic acid. The yields of products and lignin conversion were higher by C60/Bi2TiO4F2 than Bi2TiO4F2 and C60/TiO2. C60/Bi2TiO4F2 and C60/TiO2 were more stable than Bi2TiO4F2 upon repetitive recycling of catalyst. The effectiveness of C60/Bi2TiO4F2 declines 25%, whereas that of Bi2TiO4F2 declines 56.4% after being recycled five times. FTIR and HRTEM indicated that the deactivation of photocatalysts might be caused by lignin adsorbed on the surface of photocatalysts and the change in the crystal structure.}, number={5}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Du, Zhijie and Li, Wenzhi and Xu, Zhiping and Wu, Hao and Jameel, Hasan and Chang, Hou-Min and Ma, Long-Long}, year={2016}, pages={365–376} }
 @article{salam_lucia_jameel_2016, title={Chitosan-Based Reagents Endow Recycled Paper Fibers with Remarkable Physical and Antimicrobial Properties}, volume={55}, ISSN={["0888-5885"]}, DOI={10.1021/acs.iecr.6b00776}, abstractNote={The aim of the current work was to develop and study a paper additive system that endows recycled paper fibers with strong mechanical and antimicrobial properties. Five different types of modifying agents including succinic acid, carboxymethyladipic acid, butanetetracarboxylic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid (DTPA) were reacted with soy flour. Approximately 2% modified soy flour additive by mass relative to a old corrugated container (OCC) pulp slurry was mixed before generating a two-dimensional hand sheet for physical testing. DTPA-modified soy-flour-treated OCC pulp displayed better tensile relative to the results from the use of other modifying agents. Soy flour was treated with different DTPA concentrations, times, temperatures, and pH values to determine the optimal modification reaction conditions. Afterward, the DTPA–soy flour was complexed with chitosan to decrease the biodecomposition of soy protein, improve its incorporation into an OCC matrix, and ...}, number={27}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Salam, Abdus and Lucia, Lucian A. and Jameel, Hasan}, year={2016}, month={Jul}, pages={7282–7286} }
 @article{park_wang_lee_jameel_jin_park_2016, title={Effect of the Two-Stage Autohydrolysis of Hardwood on the Enzymatic Saccharification and Subsequent Fermentation with an Efficient Xylose-Utilizing Saccharomyces cerevisiae}, volume={11}, ISSN={["1930-2126"]}, DOI={10.15376/biores.11.4.9584-9595}, abstractNote={To effectively utilize sugars during the fermentation process, it is important to develop a process that can minimize the generation of inhibiting compounds such as furans and acids, and a robust micro-organism that can co-ferment both glucose and xylose into products. In this study, the feasibility of efficient ethanol production was investigated using a combination of two approaches: two-stage autohydrolysis of biomass and fermentation using an engineered Saccharomyces cerevisiae to produce ethanol. When the hardwood chips were autohydrolyzed at 140 °C, followed by the second treatment at 180 °C, a higher yield of sugar conversion and fewer inhibitory effects on subsequent fermentation were achieved compared with the results from single-stage autohydrolysis. A higher overall yield of ethanol resulted by using an engineered yeast strain, SR8. This observation suggests the possibility of the feasible combination of two-stage autohydrolysis and the recombinant yeast.}, number={4}, journal={BIORESOURCES}, author={Park, Junyeong and Wang, Ziyu and Lee, Won-Heong and Jameel, Hasan and Jin, Yong-Su and Park, Sunkyu}, year={2016}, month={Nov}, pages={9584–9595} }
 @article{pawar_venditti_jameel_chang_ayoub_2016, title={Engineering physical and chemical properties of softwood kraft lignin by fatty acid substitution}, volume={89}, ISSN={0926-6690}, url={http://dx.doi.org/10.1016/j.indcrop.2016.04.070}, DOI={10.1016/j.indcrop.2016.04.070}, abstractNote={A process to attach fatty acids to lignin is reported which alters its thermal behavior. By attaching saturated C18 fatty acids to OH groups, stable lignin stearates (LS) of controllable degrees of substitution (DS) were synthesized. Interesting physical properties were observed, wherein LS was observed to melt and flow at temperatures as low as 50 °C. Melting was possible due to the crystallization of stearate chains when LS was purified by precipitation. A NMR method was established for quantification of the degree of substitution. At very high %DS values (close to 100%), the melting phenomenon was reversible, but at low %DS, melting occurred only during the 1st heating ramp during thermal cycling. The ability of LS to plasticize polystyrene (PS) is reported wherein integral blend films containing up to 25% by weight of LS were formed. The Tg of the blended films could be lowered by 22 °C using LS relative to PS. Lignin stearates have the potential to serve as interesting compounds for their ability to plasticize not only PS but other thermoplastic materials as well.}, journal={Industrial Crops and Products}, publisher={Elsevier BV}, author={Pawar, Siddhesh N. and Venditti, Richard A. and Jameel, Hasan and Chang, Hou-Min and Ayoub, Ali}, year={2016}, month={Oct}, pages={128–134} }
 @article{culbertson_treasure_venditti_jameel_gonzalez_2016, title={Life Cycle Assessment of lignin extraction in a softwood kraft pulp mill}, volume={31}, number={1}, journal={Nordic Pulp & Paper Research Journal}, author={Culbertson, C. and Treasure, T. and Venditti, R. and Jameel, H. and Gonzalez, R.}, year={2016}, pages={30–247} }
 @article{adebawo_naithani_sadeghifar_tilotta_lucia_jameel_ogunsanwo_2016, title={Morphological and interfacial properties of chemically-modified tropical hardwood}, volume={6}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/C5RA19409A}, DOI={10.1039/C5RA19409A}, abstractNote={Chemical modification of wood with acetic anhydride is an environmentally friendly process to sustain and improve wood properties over a longer term than naturally allowed. Such an approach offers many potential and attractive product avenues for the wood industry. In this study, obeche tropical hardwood (Triplochiton scleroxylon) was acetylated with acetic anhydride to improve its mechanical and interfacial properties relative to unmodified wood; specifically, dimensional stability in terms of anti-swelling efficiency (ASE), water repellent efficiency (WRE), and hydrophobicity were the target properties of interest. The chemical modification was carried out at 120 °C with five varying reaction times (1–5 h) to optimize the reaction based on weight percent gain (WPG). It was found that as the reaction time increased, the WGP and hydrophobicity increased, but the percentage of water absorption and volumetric swelling diminished. In total, acetylation provided the hardwood with good dimensional stability. The chemically-modified wood was characterized by Fourier transform-infrared (FT-IR), dynamic contact angle, and an Owens–Wendt surface energy analysis.}, number={8}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Adebawo, F. G. and Naithani, V. and Sadeghifar, Hasan and Tilotta, D. and Lucia, L. A. and Jameel, Hasan and Ogunsanwo, O. Y.}, year={2016}, pages={6571–6576} }
 @article{huang_jeuck_du_yong_chang_jameel_phillips_2016, title={Novel process for the coproduction of xylo-oligosaccharides, fermentable sugars, and lignosulfonates from hardwood}, volume={219}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2016.08.051}, abstractNote={Many biorefineries have not been commercialized due to poor economic returns from final products. In this work, a novel process has been developed to coproduce valuable sugars, xylo-oligosaccharides, and lignosulfonates from hardwood. The modified process includes a mild autohydrolysis pretreatment, which enables for the recovery of the xylo-oligosaccharides in auto-hydrolysate. Following enzymatic hydrolysis, the residue is sulfomethylated to produce lignosulfonates. Recycling the sulfomethylation residues increased both the glucan recovery and lignosulfonate production. The glucose recovery was increased from 81.7% to 87.9%. Steady state simulation using 100 g of hardwood produced 46.7 g sugars, 5.9 g xylo-oligosaccharides, and 25.7 g lignosulfonates, which were significantly higher than that produced from the no-recycling process with 39.1 g sugars, 5.9 g xylo-oligosaccharides, and 15.0 g lignosulfonates. The results indicate that this novel biorefinery process can improve the production of fermentable sugars and lignosulfonate from hardwood as compared to a conventional biorefinery process.}, journal={BIORESOURCE TECHNOLOGY}, author={Huang, Caoxing and Jeuck, Ben and Du, Jing and Yong, Qiang and Chang, Hou-min and Jameel, Hasan and Phillips, Richard}, year={2016}, month={Nov}, pages={600–607} }
 @article{liu_li_ma_an_li_jameel_chang_2016, title={Pretreatment of corn stover for sugar production using a two-stage dilute acid followed by wet-milling pretreatment process}, volume={211}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2016.03.131}, abstractNote={A two-stage process was evaluated to increase sugar recovery. Firstly, corn stover was treated with dilute hydrochloric acid to recover the xylose, and then the residue was subjected to a wet-milling pretreatment. Dilute hydrochloric acid showed a high xylose recovery during the first stage. The optimal condition was 120 °C and 40 min for 0.7 wt% dilute hydrochloric acid pretreatment followed by wet-milling pretreatment for 15 min. The xylose and glucose yield were 81.0% and 64.0%, respectively, with a cellulase dosage at 3 FPU/g of substrate. This two-stage process was effective on account of the removal of hemicelluloses in the first stage and the delamination of cell wall in the second stage, increasing the possibility of adsorption of cellulose to enzymes, and resulting in a high sugar recovery with a very low enzyme loading.}, journal={BIORESOURCE TECHNOLOGY}, author={Liu, Qiyu and Li, Wenzhi and Ma, Qiaozhi and An, Shengxin and Li, Minghao and Jameel, Hasan and Chang, Hou-min}, year={2016}, month={Jul}, pages={435–442} }
 @article{hu_du_liu_chang_jameel_2016, title={Structural Characterization of Pine Kraft Lignin: BioChoice Lignin vs Indulin AT}, volume={36}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2016.1214732}, abstractNote={BioChoice lignin (BCL) is a newly commercialized pine kraft lignin from Plymouth Mill of Domtar, which is precipitated from black liquor of bleachable-grade pulp. Indulin AT is a pine kraft lignin commercialized by Meadwestvaco for the past 60 years, which is precipitated from black liquor of linerboard-grade pulp. Thus, the two technical lignins are produced under quite different conditions in terms of alkali charge and pulping time/temperature. While the chemical structure of Indulin AT is well documented, that of BCL is totally unknown. In this study, chemical structures of BCL and Indulin AT are characterized using modern analytical techniques and compared with those of pine milled wood lignin (MWL) in order to elucidate the structural changes that occur during kraft pulping and the structural differences, if any, between BCL and Indulin AT. Both BCL and Indulin AT are structurally very different from the native lignin (MWL) in wood, indicating drastic structural modification during the kraft pulping process. Surprisingly, BCL and Indulin AT are structurally very similar, in spite of the fact that they are produced under different process conditions. However, there are subtle structural differences between BCL and Indulin AT. BCL has higher phenolic hydroxyl, catechol, enol ether, and stilbene contents, but lower methoxyl and β-O-4 contents. These differences are explained by the different pulping conditions under which the two technical lignins are produced.}, number={6}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Hu, Zhoujian and Du, Xueyu and Liu, Jie and Chang, Hou-min and Jameel, Hasan}, year={2016}, pages={432–446} }
 @article{balakshin_capanema_santos_chang_jameel_2016, title={Structural analysis of hardwood native lignins by quantitative C-13 NMR spectroscopy}, volume={70}, ISSN={["1437-434X"]}, DOI={10.1515/hf-2014-0328}, abstractNote={Abstract Milled wood lignins from alkaline pretreated wood with very low sugar content and a wide range of syringyl-to-guaiacyl (S/G) ratio between 1.2 and 3.0 were isolated from 12 industrially valuable hardwood (HW) species. The lignin preparations were investigated by means of a comprehensive 13C nuclear magnetic resonance (NMR) methodology to address the possibilities and limitations of this approach for HW native lignins and to estimate the structural variations within HW lignins. Good correlations were found for different independent methods for the quantification of major lignin moieties. The results were reliable at the C6 level and not only for relative comparison. The correlation was good between methoxyl group determinations by wet chemistry and those by 13C NMR spectroscopy. The limitations of the 13C NMR method were also pointed out. The differences in the S/G ratios can be large, but other structural deviations are less significant. Strong correlations between the S/G ratios and the amounts of other structural peculiarities could not be found by the 13C NMR approach. However, with increasing S/G ratios, the β-O-4 content showed increasing tendencies and the degree of condensation showed decreasing tendencies.}, number={2}, journal={HOLZFORSCHUNG}, author={Balakshin, Mikhail Yu and Capanema, Ewellyn A. and Santos, Ricardo B. and Chang, Hou-min and Jameel, Hasan}, year={2016}, month={Feb}, pages={95–108} }
 @article{salam_lucia_jameel_2015, title={A New Class of Biobased Paper Dry Strength Agents: Synthesis and Characterization of Soy-Based Polymers}, volume={3}, ISSN={["2168-0485"]}, DOI={10.1021/sc500764m}, abstractNote={The goal of the current effort was to develop a new soy-based (soy flour) derivative to impart high fiber–fiber strength improvements to two-dimensional paper sheets. The success of the research hinged on successful proliferation of carboxylic and/or amine functionalities onto the polymeric backbone of the soy flour to significantly contribute to improved interfiber bonding of the paper–fiber sheets. Diethylenetriaminepentaacetic acid (DTPA) was reacted with soy flour in the presence of sodium hypophosphite and complexed with chitosan for the development of a new class of dry strength agents to improve integration into pulp fibers and thus increase interfiber bonding. The synthetic conditions including surface modifier concentration, time, temperature, pH, and material-to-liquor ratio were optimized. The paper materials incorporating the DTPA cross-linked (modified) soy flour agent demonstrated unprecedented tensile strength increases. A 1% soy protein flour–DTPA–-chitosan agent by mass of pulp-based slur...}, number={3}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Salam, Abdus and Lucia, Lucian A. and Jameel, Hasan}, year={2015}, month={Mar}, pages={524–532} }
 @article{han_jin_jameel_chang_phillips_park_2015, title={Autohydrolysis Pretreatment of Waste Wheat Straw for Cellulosic Ethanol Production in a Co-located Straw Pulp Mill}, volume={175}, ISSN={["1559-0291"]}, DOI={10.1007/s12010-014-1349-5}, abstractNote={Waste wheat straw (WWS) is the waste product from feedstock preparation process in a straw pulp mill. It has a significant annual production rate and no commercial value has been explored on this material. In this study, waste wheat straw was pretreated using an autohydrolysis process followed by mechanical refining, and the pretreated materials were further enzymatically hydrolyzed to evaluate the total sugar recovery for bioethanol production. Results show that autohydrolysis at 170 °C for 40 min followed by 6000 revolution PFI refining provided the best result in this study, where a total sugar recovery (total sugars in autohydrolysis filtrate and enzymatic hydrolyzate over total carbohydrates on raw WWS) of 70 % at 4 filter paper unit per oven dry gram (FPU/OD g) substrate enzyme charge could be obtained. The economic evaluation of this biorefinery process indicates that cellulosic ethanol production from autohydrolysis of WWS is a very profitable business, with 28.4 % of internal rate of return can be achieved based on current ethanol wholesale price in China.}, number={2}, journal={APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY}, author={Han, Qiang and Jin, Yanbin and Jameel, Hasan and Chang, Hou-min and Phillips, Richard and Park, Sunkyu}, year={2015}, month={Jan}, pages={1193–1210} }
 @article{xu_li_du_wu_jameel_chang_ma_2015, title={Conversion of corn stalk into furfural using a novel heterogeneous strong acid catalyst in gamma-valerolactone}, volume={198}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2015.09.104}, abstractNote={A novel solid acid catalyst was prepared by the copolymerization of p-toluenesulfonic acid and paraformaldehyde and then characterized by FT-IR, TG/DTG, HRTEM and N2-BET. Furfural was successfully produced by the dehydration of xylose and xylan using the novel catalyst in γ-valerolactone. This investigation focused on effects of various reaction conditions including solvent, acid catalyst, reaction temperature, residence time, water concentration, xylose loading and catalyst dosage on the dehydration of xylose to furfural. It was found that the solid catalyst displayed extremely high activity for furfural production. 80.4% furfural yield with 98.8% xylose conversion was achieved at 170°C for 10 min. The catalyst could be recycled at least five times without significant loss of activity. Furthermore, 83.5% furfural yield and 19.5% HMF yield were obtained from raw corn stalk under more severe conditions (190°C for 100 min).}, journal={BIORESOURCE TECHNOLOGY}, author={Xu, Zhiping and Li, Wenzhi and Du, Zhijie and Wu, Hao and Jameel, Hasan and Chang, Hou-min and Ma, Longlong}, year={2015}, month={Dec}, pages={764–771} }
 @article{salam_lucia_jameel_2015, title={Fluorine-based surface decorated cellulose nanocrystals as potential hydrophobic and oleophobic materials}, volume={22}, ISSN={0969-0239 1572-882X}, url={http://dx.doi.org/10.1007/S10570-014-0507-9}, DOI={10.1007/S10570-014-0507-9}, number={1}, journal={Cellulose}, publisher={Springer Science and Business Media LLC}, author={Salam, Abdus and Lucia, Lucian A. and Jameel, Hasan}, year={2015}, month={Feb}, pages={397–406} }
 @article{capanema_balakshin_katahira_chang_jameel_2015, title={HOW WELL DO MWL AND CEL PREPARATIONS REPRESENT THE WHOLE HARDWOOD LIGNIN?}, volume={35}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2014.892993}, abstractNote={Hardwood lignin preparations were isolated using classical milled wood lignin (MWL) and cellulolytic enzyme lignin (CEL) protocols. Furthermore, we managed to produce a lignin preparation of a very high yield, above 90%, with high purity and minimal structural degradation. This was achieved by dissolution and regeneration of milled wood prior to enzymatic hydrolysis, along with the use of 80% dioxane for lignin extraction. This preparation (RCEL-80) yield was about 4.5 and 2.5 times higher than the yields of the traditional MWL and CEL preparations, correspondingly, at the same milling time. The preparations obtained were comprehensively analyzed with state-of-the-art quantitative NMR techniques and wet chemistry methods. CELs were representative preparations for hardwood lignins as the S/G ratios in the CELs were equivalent to those in lignin in situ. Degradation of the main lignin subunits was very low. Importantly, the structures of CELs were independent of the preparation yield and were very similar to the structure of the high-yield lignin, RCEL-80. In contrast, the structures of MWLs were noticeably dependent on the preparation yield, especially when the yield was below 15–20% of total wood lignin. In particular, the S/G ratio increased with increasing MWL yield, but was still lower than the S/G ratios of the whole lignins in situ, even at high MWL yields. The amounts of β-O-4 lignin units in MWL were lower than those in the corresponding CEL preparations. It has been concluded that CEL preparations were representative of the whole wood lignin whereas MWLs represent a fraction with a lower S/G ratio.}, number={1}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Capanema, Ewellyn and Balakshin, Mikhail and Katahira, Rui and Chang, Hou-min and Jameel, Hasan}, year={2015}, pages={17–26} }
 @article{almeida_santos_hart_jameel_2015, title={Hardwood pulping kinetics of bulk and residual phases}, volume={14}, number={10}, journal={TAPPI Journal}, author={Almeida, D. and Santos, R. B. and Hart, P. W. and Jameel, H.}, year={2015}, pages={652–662} }
 @article{ferrer_vargas_jameel_rojas_2015, title={Influence of operating variables and model to minimize the use of anthraquinone in the soda-anthraquinone pulping of barley straw}, volume={10}, DOI={10.15376/biores.10.4.6442-6456}, abstractNote={Soda-anthraquinone (soda-AQ) pulping of barley straw was used to obtain cellulosic pulps for papermaking purposes. The identified parameters, or variables to be optimized, were operating time, anthraquinone concentration, and PFI refiner revolutions, and the influence of these operating variables on pulp properties was studied. A polynomial model that reproduced the experimental results with errors less than 6% was developed. Operating variables were found (46 min of processing time, 0.4 wt.% of anthraquinone concentration, and 3000 rpm of PFI revolution) that yielded competitive pulp properties (82 °SR beating grade number, 870 mL/g of viscosity, Kappa number of 13, 77 Nm/g of tensile index, and 30% ISO brightness) at reasonable chemical and energy costs. On the other hand, this study highlights the usefulness of this polynomial model as a method to minimize the use of anthraquinone in these pulping processes and to be able to predict what the pulp properties will be. For comparison purposes, new operating conditions were found, and the pulp properties still remain at a very good level for this cereal straw.}, number={4}, journal={BioResources}, author={Ferrer, A. and Vargas, F. and Jameel, H. and Rojas, O. J.}, year={2015}, pages={6442–6456} }
 @article{fritz_ferrer_salas_jameel_rojas_2015, title={Interactions between Cellulolytic Enzymes with Native, Autohydrolysis, and Technical Lignins and the Effect of a Polysorbate Amphiphile in Reducing Nonproductive Binding}, volume={16}, ISSN={["1526-4602"]}, DOI={10.1021/acs.biomac.5b01203}, abstractNote={Understanding enzyme-substrate interactions is critical in designing strategies for bioconversion of lignocellulosic biomass. In this study we monitored molecular events, in situ and in real time, including the adsorption and desorption of cellulolytic enzymes on lignins and cellulose, by using quartz crystal microgravimetry and surface plasmon resonance. The effect of a nonionic surface active molecule was also elucidated. Three lignin substrates relevant to the sugar platform in biorefinery efforts were considered, namely, hardwood autohydrolysis cellulolytic (HWAH), hardwood native cellulolytic (MPCEL), and nonwood native cellulolytic (WSCEL) lignin. In addition, Kraft lignins derived from softwoods (SWK) and hardwoods (HWK) were used as references. The results indicated a high affinity between the lignins with both, monocomponent and multicomponent enzymes. More importantly, the addition of nonionic surfactants at concentrations above their critical micelle concentration reduced remarkably (by over 90%) the nonproductive interactions between the cellulolytic enzymes and the lignins. This effect was hypothesized to be a consequence of the balance of hydrophobic and hydrogen bonding interactions. Moreover, the reduction of surface roughness and increased wettability of lignin surfaces upon surfactant treatment contributed to a lower affinity with the enzymes. Conformational changes of cellulases were observed upon their adsorption on lignin carrying preadsorbed surfactant. Weak electrostatic interactions were determined in aqueous media at pH between 4.8 and 5.5 for the native cellulolytic lignins (MPCEL and WSCEL), whereby a ∼20% reduction in the enzyme affinity was observed. This was mainly explained by electrostatic interactions (osmotic pressure effects) between charged lignins and cellulases. Noteworthy, adsorption of nonionic surfactants onto cellulose, in the form cellulose nanofibrils, did not affect its hydrolytic conversion. Overall, our results highlight the benefit of nonionic surfactant pretreatment to reduce nonproductive enzyme binding while maintaining the reactivity of the cellulosic substrate.}, number={12}, journal={BIOMACROMOLECULES}, author={Fritz, Consuelo and Ferrer, Ana and Salas, Carlos and Jameel, Hasan and Rojas, Orlando J.}, year={2015}, month={Dec}, pages={3878–3888} }
 @misc{li_zhang_du_ma_jameel_chang_2015, title={Photocatalytic degradation of lignin model compounds and kraft pine lignin by CdS/TiO2 under visible light irradiation}, volume={10}, DOI={10.15376/biores.10.1.1245-1259}, abstractNote={Cadium sulfide/titanium dioxide (CdS/TiO2) catalyst was prepared by two different methods: microemulsion-mediated solvothermal hydrolyzation (CdS/TiO2 (SH)) and in-situ sulfurization under supercritical conditions (CdS/TiO2 (SS)). The photocatalysts were characterized by nitrogen adsorption-desorption, X-ray diffraction, X-ray photoelectron spectra, UV-Vis absorption spectra, and PL spectra. Photodegradation reactions of three monomeric and one dimeric lignin model compounds, and kraft pine lignin (Indulin AT) were carried out at room temperature in a weak alkaline aqueous system by visible light irradiation with air bubbling. Quantitative results showed that these lignin model compounds and kraft lignin were effectively degraded. While both phenolic and non-phenolic lignin units are reactive, the phenolic units appeared to react faster and preferentially reacted.}, number={1}, journal={BioResources}, author={Li, W. Z. and Zhang, M. J. and Du, Z. J. and Ma, Q. Z. and Jameel, H. and Chang, H. M.}, year={2015}, pages={1245–1259} }
 @article{ribas batalha_han_jameel_chang_colodette_borges gomes_2015, title={Production of fermentable sugars from sugarcane bagasse by enzymatic hydrolysis after autohydrolysis and mechanical refining}, volume={180}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2014.12.060}, abstractNote={The autohydrolysis process has been considered a simple, low-cost and environmental friendly technology for generation of sugars from biomass. In order to improve accessibility of enzymes during enzymatic hydrolysis as well as to allow the recovery of hemicellulose in the filtrate, the sugarcane bagasse was pretreated using autohydrolysis followed by a mechanical refining process. The autohydrolysis was carried out in three different conditions. Autohydrolysis at 190 °C for 10 min provided the highest overall sugar (19.2/100 g raw bagasse) in prehydrolyzate. The enzymatic hydrolysis step was performed for all the post-treated solids with and without refining at enzyme loadings of 5 and 10 FPU/g for 96 h. A total of 84.4% of sugar can be recovered from sugarcane bagasse at 180 °C for 20 min with 5 FPU/g enzyme charge. The economic analysis for the proposed method showed that the bioethanol production can have a financial return larger than 12%.}, journal={BIORESOURCE TECHNOLOGY}, author={Ribas Batalha, Larisse Aparecida and Han, Qiang and Jameel, Hasan and Chang, Hou-min and Colodette, Jorge Luiz and Borges Gomes, Fernando Jose}, year={2015}, month={Mar}, pages={97–105} }
 @article{geng_jin_jameel_park_2015, title={Strategies to achieve high-solids enzymatic hydrolysis of dilute-acid pretreated corn stover}, volume={187}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2015.03.067}, abstractNote={Three strategies were presented to achieve high solids loading while maximizing carbohydrate conversion, which are fed-batch, splitting/thickening, and clarifier processes. Enzymatic hydrolysis was performed at water insoluble solids (WIS) of 15% using washed dilute-acid pretreated corn stover. The carbohydrate concentration increased from 31.8 to 99.3g/L when the insoluble solids content increased from 5% to 15% WIS, while the final carbohydrate conversion was decreased from 78.4% to 73.2%. For the fed-batch process, a carbohydrate conversion efficiency of 76.8% was achieved when solid was split into 60:20:20 ratio, with all enzymes added first. For the splitting/thickening process, a carbohydrate conversion of 76.5% was realized when the filtrate was recycled to simulate a steady-state process. Lastly, the clarifier process was evaluated and the highest carbohydrate conversion of 81.4% was achieved. All of these results suggests the possibility of enzymatic hydrolysis at high solids to make the overall conversion cost-competitive.}, journal={BIORESOURCE TECHNOLOGY}, author={Geng, Wenhui and Jin, Yongcan and Jameel, Hasan and Park, Sunkyu}, year={2015}, month={Jul}, pages={43–48} }
 @article{xiang_sen_roy_min_savithri_jameel_chiang_chang_2015, title={Wood characteristics and enzymatic saccharification efficiency of field-grown transgenic black cottonwood with altered lignin content and structure}, volume={22}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-014-0541-7}, number={1}, journal={CELLULOSE}, author={Xiang, Zhouyang and Sen, Suman Kumar and Roy, Aparna and Min, Douyong and Savithri, Dhanalekshmi and Jameel, Hasan and Chiang, Vincent and Chang, Hou-min}, year={2015}, month={Feb}, pages={683–693} }
 @article{chen_han_venditti_jameel_2015, title={enzymatic hydrolysis of pretreated newspaper having high lignin content for bioethanol production}, volume={10}, DOI={10.15376/biores.10.3.4077-4098}, abstractNote={Recovered papers are suitable biomass sources for conversion into sugars that can be used in bioethanol production. However, paper materials with a high lignin content have been found to be recalcitrant to enzymatic hydrolysis. To address this issue, several biomass pretreatment methods were employed to evaluate their efficiency on the conversion of newspaper with high lignin content to sugar. Autohydrolysis, a hot water treatment, was identified to adversely affect sugar conversion, presumably as a result of pore collapse under high-temperature pretreatment. Flexo ink, used in newspaper printing, had no effect on the enzymatic hydrolysis, with or without autohydrolysis. The ink was still detachable after autohydrolysis, as measured by hyperwashing. Compared to untreated newspaper, separate treatments of either mechanical refining or a non-ionic surfactant (sorbitan polyoxyethylene monooleate) improved the sugar conversion by 10% at enzyme dosages of 2 and 8 FPU/g substrate. The combination of both refining and surfactant resulted in the highest sugar conversions, i.e., 46.3%, 56.7%, and 64.1% at 2, 4, and 8 FPU/g enzyme dosages, respectively. Oxidative pretreatment (oxygen, 100 °C) marginally increased the sugar conversion, whereas alkaline and green liquor (NaCO3 and Na2S) pretreatments (at 160 °C) had either no effect or decreased the sugar conversion. Based on the results of the pretreatments, higher pretreatment temperatures of newsprint negatively impacted subsequent enzyme hydrolysis.}, number={3}, journal={BioResources}, author={Chen, H. and Han, Q. and Venditti, Richard and Jameel, H.}, year={2015}, pages={4077–4098} }
 @article{salam_lucia_jameel_2014, title={A preliminary assay of the potential of soy protein isolate and its hydrolysates to provide interfiber bonding enhancements in lignocellulosic furnishes}, volume={85}, ISSN={["1873-166X"]}, DOI={10.1016/j.reactfunctpolym.2014.09.021}, abstractNote={Soy protein isolate (SPI) was extracted from soy flour and hydrolyzed with hydrochloric acid, sodium hydroxide, and enzyme, separately, to provide a series of hydrolysates. The SPI and its hydrolysis products were later cross-linked with ethylendiaminetetraacetic acid (EDTA) in the presence of sodium hypophosphite (SPH) after which they were complexed to chitosan as part of an on-going general chemical strategy in our laboratories to improve their incorporation into old corrugated container (OCC) matrix and thus increase inter-fiber bonding. Approximately 2% SPI-EDTA-chitosan and hydrolyzed SPI-EDTA-chitosan additives by mass (OCC-based slurry) were thoroughly mixed before generating a sheet for physical testing. The tensile and burst indices of the SPI-EDTA-chitosan additive-treated OCC pulp sheet increased 46.3% and 61.85%, respectively, while the inter fiber bonding of SPI-EDTA-chitosan additive-treated OCC pulp sheet increased 74.86% compared to the control, albeit having a decreased tear strength and roughness, with significantly increased gloss. The additive-treated pulp sheet was characterized by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and ATR to provide evidence for product synthesis.}, journal={REACTIVE & FUNCTIONAL POLYMERS}, author={Salam, Abdus and Lucia, Lucian A. and Jameel, Hasan}, year={2014}, month={Dec}, pages={228–234} }
 @article{ertas_han_jameel_2014, title={Acid-catalyzed autohydrolysis of wheat straw to improve sugar recovery}, volume={169}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2014.06.081}, abstractNote={A comparison study of autohydrolysis and acid-catalyzed autohydrolysis of wheat straw was performed to understand the impact of acid addition on overall sugar recovery. Autohydrolysis combined with refining is capable of achieving sugar recoveries in the mid 70s. If the addition of a small amount of acid is capable of increasing the sugar recovery even higher it may be economically attractive. Acetic, sulfuric, hydrochloric and sulfurous acids were selected for acid-catalyzed autohydrolysis pretreatments. Autohydrolysis with no acid at 190 °C showed the highest total sugar in the prehydrolyzate. Enzymatic hydrolysis was performed for all the post-treated solids with and without refining at enzyme loadings of 4 and 10 FPU/g for 96 h. Acid-catalyzed autohydrolysis at 190 °C with sulfurous acid showed the highest total sugar recovery of 81.2% at 4 FPU/g enzyme charge compared with 64.3% at 190 °C autohydrolysis without acid.}, journal={BIORESOURCE TECHNOLOGY}, author={Ertas, Murat and Han, Qiang and Jameel, Hasan}, year={2014}, month={Oct}, pages={1–8} }
 @article{andrade_colodette_jameel_2014, title={Chemical and morphological characterization of sugar cane bagasse}, volume={13}, number={6}, journal={TAPPI Journal}, author={Andrade, M. F. and Colodette, J. L. and Jameel, H.}, year={2014}, pages={27–33} }
 @article{jones_venditti_park_jameel_2014, title={Comparison of lab, pilot, and industrial scale low consistency mechanical refining for improvements in enzymatic digestibility of pretreated hardwood}, volume={167}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2014.06.026}, DOI={10.1016/j.biortech.2014.06.026}, abstractNote={Mechanical refining has been shown to improve biomass enzymatic digestibility. In this study industrial high-yield sodium carbonate hardwood pulp was subjected to lab, pilot and industrial refining to determine if the mechanical refining improves the enzymatic hydrolysis sugar conversion efficiency differently at different refining scales. Lab, pilot and industrial refining increased the biomass digestibility for lignocellulosic biomass relative to the unrefined material. The sugar conversion was increased from 36% to 65% at 5 FPU/g of biomass with industrial refining at 67.0 kWh/t, which was more energy efficient than lab and pilot scale refining. There is a maximum in the sugar conversion with respect to the amount of refining energy. Water retention value is a good predictor of improvements in sugar conversion for a given fiber source and composition. Improvements in biomass digestibility with refining due to lab, pilot plant and industrial refining were similar with respect to water retention value.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Jones, Brandon W. and Venditti, Richard and Park, Sunkyu and Jameel, Hasan}, year={2014}, month={Sep}, pages={514–520} }
 @article{geng_huang_jin_song_chang_jameel_2014, title={Comparison of sodium carbonate-oxygen and sodium hydroxide-oxygen pretreatments on the chemical composition and enzymatic saccharification of wheat straw}, volume={161}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2014.03.024}, abstractNote={Pretreatment of wheat straw with a combination of sodium carbonate (Na2CO3) or sodium hydroxide (NaOH) with oxygen (O2) 0.5 MPa was evaluated for its delignification ability at relatively low temperature 110 °C and for its effect on enzymatic hydrolysis efficiency. In the pretreatment, the increase of alkali charge (as Na2O) up to 12% for Na2CO3 and 6% for NaOH, respectively, resulted in enhancement of lignin removal, but did not significantly degrade cellulose and hemicellulose. When the pretreated solid was hydrolyzed with a mixture of cellulases and hemicellulases, the sugar yield increased rapidly with the lignin removal during the pretreatment. A total sugar yield based on dry matter of raw material, 63.8% for Na2CO3–O2 and 71.9% for NaOH–O2 was achieved under a cellulase loading of 20 FPU/g-cellulose. The delignification efficiency and total sugar yield from enzymatic hydrolysis were comparable to the previously reported results at much higher temperature without oxygen.}, journal={BIORESOURCE TECHNOLOGY}, author={Geng, Wenhui and Huang, Ting and Jin, Yongcan and Song, Junlong and Chang, Hou-min and Jameel, Hasan}, year={2014}, month={Jun}, pages={63–68} }
 @article{chen_han_daniel_venditti_jameel_2014, title={Conversion of Industrial Paper Sludge to Ethanol: Fractionation of Sludge and Its Impact}, volume={174}, ISSN={0273-2289 1559-0291}, url={http://dx.doi.org/10.1007/s12010-014-1083-z}, DOI={10.1007/s12010-014-1083-z}, abstractNote={Paper sludge is an attractive biomass source for the conversion to ethanol due to its low cost and the lack of severe pretreatment required. Four sludges from pulp and paper operations including both virgin kraft (VK) and recycled and deinking (RD) paper mills were analyzed. A fractionation process using a laboratory screen was utilized to produce a fiber-rich stream for enzymatic hydrolysis. This process removed 82-98 % of the ash with fiber yields from 39 to 69 %. Even though sludges in both non-fractionated and fractionated scenarios were pH-adjusted, total sugar conversion was still improved by 12-27 % by fractionation with 4.5 times less acid required for pH adjustment. Fermentation of the fractionated sludges showed very high ethanol yields. Acid insoluble clay adsorbs 3-5 mg enzyme per gram of clay depending on enzyme dosage. Acid soluble CaCO3 adsorbs about half of the enzyme compared to clay. Fractionation efficiency was also evaluated by testing different size mesh screen openings (100 to 500 mesh). The 400-mesh screen presented the best fiber yield, ash removal and ash fractionation ratio for both VK and RD sludges. The ash-rich streams have a lower C/N ratio than the original sludge which improves its suitability as soil amendment.}, number={6}, journal={Applied Biochemistry and Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Chen, Hui and Han, Qiang and Daniel, Kevin and Venditti, Richard and Jameel, Hasan}, year={2014}, month={Aug}, pages={2096–2113} }
 @article{chen_venditti_gonzalez_phillips_jameel_park_2014, title={Economic evaluation of the conversion of industrial paper sludge to ethanol}, volume={44}, ISSN={0140-9883}, url={http://dx.doi.org/10.1016/j.eneco.2014.04.018}, DOI={10.1016/j.eneco.2014.04.018}, abstractNote={The conversion of industrial paper sludge to ethanol was simulated using engineering process simulation software loaded with laboratory generated conversion data and financially analyzed. In one scenario, sludge is fractionated to remove ash, generating a higher concentration carbohydrate stream for separate hydrolysis and fermentation (SHF). In a second scenario, non-fractionated sludge is processed with only pH adjustment. Four primary sludges from mills producing either virgin or recycled paper were analyzed and the experimental conversion results used to inform the simulations. Financial analysis was conducted assuming ethanol wholesale price of US$ 0.608 per liter. The most profitable case was fractionated virgin sludge (from a virgin paper mill) to ethanol (F-VK1) with a net present value (NPV) of US$ 11.4 million, internal rate of return (IRR) of 28%, payback period of 4.4 years and minimum ethanol revenue (MER) of US$ 0.32 per liter. Risk analysis showed that the F-VK1 case obtained a near 100% probability of business success with both central and bearish (pessimistic) assumptions.}, journal={Energy Economics}, publisher={Elsevier BV}, author={Chen, Hui and Venditti, Richard and Gonzalez, Ronalds and Phillips, Richard and Jameel, Hasan and Park, Sunkyu}, year={2014}, month={Jul}, pages={281–290} }
 @article{yu_gwak_treasure_jameel_chang_park_2014, title={Effect of Lignin Chemistry on the Enzymatic Hydrolysis of Woody Biomass}, volume={7}, ISSN={["1864-564X"]}, DOI={10.1002/cssc.201400042}, abstractNote={The impact of lignin-derived inhibition on enzymatic hydrolysis is investigated by using lignins isolated from untreated woods and pretreated wood pulps. A new method, biomass reconstruction, for which isolated lignins are precipitated onto bleached pulps to mimic lignocellulosic biomass, is introduced, for the first time, to decouple the lignin distribution issue from lignin chemistry. Isolated lignins are physically mixed and reconstructed with bleached pulps. Lignins obtained from pretreated woods adsorb two to six times more cellulase than lignins obtained from untreated woods. The higher adsorption of enzymes on lignin correlates with decreased carbohydrate conversion in enzymatic hydrolysis. In addition, the reconstructed softwood substrate has a lower carbohydrate conversion than the reconstructed hardwood substrate. The degree of condensation of lignin increases significantly after pretreatment, especially with softwood lignins. In this study, the degree of condensation of lignin (0.02 to 0.64) and total OH groups in lignin (1.7 to 1.1) have a critical impact on cellulase adsorption (9 to 70%) and enzymatic hydrolysis (83.2 to 58.2%); this may provide insights into the more recalcitrant nature of softwood substrates.}, number={7}, journal={CHEMSUSCHEM}, author={Yu, Zhiying and Gwak, Ki-Seob and Treasure, Trevor and Jameel, Hasan and Chang, Hou-min and Park, Sunkyu}, year={2014}, month={Jul}, pages={1942–1950} }
 @article{huo_li_zhang_fan_chang_jameel_2014, title={Effective C-O Bond Cleavage of Lignin beta-O-4 Model Compounds: A New RuHCl(CO)(PPh3)(3)/KOH Catalytic System}, volume={144}, ISSN={["1572-879X"]}, DOI={10.1007/s10562-014-1264-y}, number={7}, journal={CATALYSIS LETTERS}, author={Huo, Wei and Li, Wenzhi and Zhang, Minjian and Fan, Wei and Chang, Hou-min and Jameel, Hasan}, year={2014}, month={Jul}, pages={1159–1163} }
 @article{meng_geng_ren_jin_chang_jameel_2014, title={Enhancement of enzymatic saccharification of poplar by green liquor pretreatment}, volume={9}, DOI={10.15376/biores.9.2.3236-3247}, abstractNote={Green liquor (Na2S + Na2CO3, GL) pretreatment is an effective pathway for improving the enzymatic digestibility of lignocellulosic biomass for the production of bioethanol. In this work, GL was employed as a pretreatment to enhance the enzymatic saccharification of poplar. During pretreatment, the increase of H-factor and TTA charge resulted in enhanced delignification and increased degradation of polysaccharides. The sugar yield of enzymatic hydrolysis increased rapidly with increasing TTA charge in GL pretreatment, while the effect of different H-factors (from 400 to 800) on sugar yield was unnoticeable. The pretreated solid recovery was 75.5% at a lignin removal rate of 29.2% under optimized conditions of total titratable alkali (TTA) charge 20%, sulfidity 25%, and H-factor 400. The sugar yield of glucan, xylan, and total sugar of GL-pretreated poplar in enzymatic hydrolysis reached up to 89.9%, 65.5%, and 82.8%, respectively, at a cellulase loading of 40 FPU/g-cellulose.}, number={2}, journal={BioResources}, author={Meng, X. and Geng, W. H. and Ren, H. and Jin, Y. C. and Chang, H. M. and Jameel, H.}, year={2014}, pages={3236–3247} }
 @article{ertas_han_jameel_chang_2014, title={Enzymatic hydrolysis of autohydrolyzed wheat straw followed by refining to produce fermentable sugars}, volume={152}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2013.11.026}, abstractNote={Wheat straw was pretreated using an autohydrolysis process with different temperatures (160-200 °C) and times (10-20 min) in order to allow the recovery of hemicellulose in the filtrate and help open up the structure of the biomass for improved accessibility of enzymes during enzymatic hydrolysis. Autohydrolysis at 190 °C for 10 min provided the highest overall sugar (12.2/100g raw wheat straw) in the autohydrolysis filtrate and recovered 62.3% of solid residue. Before enzymatic hydrolysis, the pulps obtained from each pretreatment condition were subjected to a refining post-treatment to improve enzyme accessibility. Enzymatic hydrolysis was performed for all the pretreated solids with and without refining post-treatment at the enzyme loadings of 4 and 10 FPU/g oven dry substrate for 96 h. A total of 30.4 g sugars can be recovered from 100g wheat straw at 180 °C for 20 min with 4 FPU/g enzyme charge.}, journal={BIORESOURCE TECHNOLOGY}, author={Ertas, Murat and Han, Qiang and Jameel, Hasan and Chang, Hou-min}, year={2014}, month={Jan}, pages={259–266} }
 @article{chi_liu_jameel_zhang_zhang_2014, title={Hydrothermal pretreatment of hardwood chips prior to alkaline pulping and D-0(E-P)D-1 bleaching}, volume={9}, DOI={10.15376/biores.9.4.6193-6204}, abstractNote={In this study, mixed southern hardwood was pretreated via a hydrothermal process at 160 °C for 1 h. Alkaline pulping was then conducted on both the pretreated and original chips to prepare pulp with Kappa 17 and 30. For the Kappa 30 pulps, oxygen delignification was further carried out to render Kappa 17. After pulping, the different pulps with similar Kappa 17 were bleached by the D0(EP)D1 sequence. Pulping results show that the pretreated chips are easier to cook and necessitate less alkaline charge to achieve a similar Kappa without decreasing the pulp viscosity. Under similar bleaching conditions, hydrothermal pretreatment leads to pulps with a higher brightness, viscosity, and paper sheet opacity and scattering coefficient, while also lowering the burst and tensile strength. Furthermore, the pulp fiber length, fiber width, and percentage of fines decreases, yet the coarseness, curl index, and kink index increase. However, the paper properties of bleached pulps are not improved significantly when subjected to modified continuous cooking (MCC) pulping or oxygen delignification.}, number={4}, journal={BioResources}, author={Chi, C. C. and Liu, M. and Jameel, H. and Zhang, S. F. and Zhang, Z.}, year={2014}, pages={6193–6204} }
 @article{min_xiang_liu_jameel_chiang_jin_chang_2014, title={Improved Protocol for Alkaline Nitrobenzene Oxidation of Woody and Non-Woody Biomass}, volume={35}, ISSN={0277-3813 1532-2319}, url={http://dx.doi.org/10.1080/02773813.2014.902965}, DOI={10.1080/02773813.2014.902965}, abstractNote={The protocol of alkaline nitrobenzene oxidation was investigated to improve its ability to identify the different lignin structures for both woody and non-woody biomass. The survival factors of all six oxidation products—syringaldehde (Sr), vanillin (V), p-hydroxybenzaldehyde (B) and their corresponding acids, syringic acid (Sa), vanillic acid (Va), and p-hydroxybenzoic acid (Ba)—were studied at 170, 180, and 190°C for several residence times. Under similar conditions, various lignin model compounds—a softwood (loblolly pine), a hardwood (red maple), and a non-wood raw material (corn stover)—were oxidized. Molar yields of oxidation products were determined and the ratios of (Sr+Sa)/(V+Va), (Sr/V), and B/(V+Va) (B/V) were calculated. All oxidation products were relatively stable at 170 and 180°C but showed some degradation at 190°C, especially at long residence time. In all cases, p-hydroxybenzoic acid was barely detectable. While yields of oxidation products reach a maximum at 170°C for pine and maple, maximal yields of corn stover require 190°C. Consequently, we recommend that nitrobenzene oxidation be carried out at 170°C for 2.5 h for softwood and hardwood, but at 190°C and 4 h with correction for the survival factors for corn stover and other non-woody biomass. Alternatively, a protocol of oxidation at two temperatures is recommended for non-woody biomass.}, number={1}, journal={Journal of Wood Chemistry and Technology}, publisher={Informa UK Limited}, author={Min, Douyong and Xiang, Zhouyang and Liu, Jie and Jameel, Hasan and Chiang, Vincent and Jin, Yongcan and Chang, Hou-min}, year={2014}, month={Sep}, pages={52–61} }
 @article{treasure_gonzalez_jameel_phillips_park_kelley_2014, title={Integrated conversion, financial, and risk modeling of cellulosic ethanol from woody and non-woody biomass via dilute acid pre-treatment}, volume={8}, ISSN={1932-104X}, url={http://dx.doi.org/10.1002/bbb.1494}, DOI={10.1002/bbb.1494}, abstractNote={Dilute sulfuric acid pre‐treatment followed by enzymatic hydrolysis and fermentation is a technology widely studied as a potential pathway for conversion of lignocellulosic biomass to ethanol. Six feedstocks were evaluated in process and financial simulations. The woody feedstocks include natural hardwood, Eucalyptus, and loblolly pine while the non‐woody feedstocks include corn stover, switchgrass, and sweet sorghum. Based on experimental and literature data, ethanol yields for the non‐woody biomasses range from 315 to 328 liters per bone dry metric ton (L/BDt). Sweet sorghum that is pressed and washed to remove soluble sugars prior to dilute acid processing can have an ethanol yield of approximately 470 L/BDt. Natural hardwood and Eucalyptus produce ethanol yields of 336 and 309 L/BDt, respectively. When processing 700 000 bone dry metric tons per year, the non‐woody biomasses have lower minimum ethanol revenues to achieve a 12% internal rate of return (MER@12%) than the woody biomasses. The non‐wood MER@12% ranged from $0.70 to $080/liter while the MER@12% for natural hardwood and Eucalyptus was $0.84–$0.85/liter. The impact of feedstock composition variability on the net present value at 12% (NPV@12%) discount was estimated for corn stover, switchgrass, and loblolly pine. One standard deviation in the sample carbohydrate content for corn stover, switchgrass, and loblolly pine will impact the NPV@12% by approximately $40 M, $72 M, and $24 M, respectively. If recent historical cost and revenue variability continues for the life of the project the most attractive feedstock is squeezed sweet sorghum where the probability of achieving at least a 12% internal rate of return is 64%.}, number={6}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Treasure, Trevor and Gonzalez, Ronalds and Jameel, Hasan and Phillips, Richard B. and Park, Sunkyu and Kelley, Steve}, year={2014}, month={May}, pages={755–769} }
 @inproceedings{salam_jameel_liu_lucia_2014, title={Novel class of soy flour biobased functional additives for dry strength enhancements in recovered and virgin pulp fiber networks}, volume={1178}, DOI={10.1021/bk-2014-1178.ch011}, abstractNote={The domain of paper/pulp fiber dry strength has witnessed a paucity of research efforts over the last decade. Soy flour as a potential new comer to the field is a modestly priced, yet complex glycoprotein-based biomacromolecule compared to a number of other paper dry strength biomacromolecules such as cationized starch, carboxymethyl cellulose (CMC), and guar gum. Nevertheless, and perhaps more importantly, it possesses a relatively rich hydrogen-bonding surface functional density, but high susceptibility to bacterial digestion due to its (mainly) protein-based composition. Unfortunately, within the construct of any commercial paper-based applications, the results of the digestion are a characteristically unpleasant odor, machine fouling, and potential paper strength losses, vital issues to consider for its potential application as a dry strength additive. The installation of carboxylic and amine groups onto the surface of soy flour for addressing the latter issues offers an attractive solution. In the present chapter, paper dry strength data after the application of soy flour modified with diethylenetriaminetetracaetic acid (DTPA) and further crosslinked with chitosan are presented. The synthesis conditions, reactant concentration, time, temperature and pH were evaluated with the objective of mechanical property optimization in the final paper-based sheet. The tensile indices of modified soy flour additive-treated recycled OCC pulp sheets, NSSC (virgin) pulp sheets, and kraft (virgin) pulp sheets increased by 52%, 53%, and 58%, respectively, while the inter-fiber bonding strength increased 2.5-3.0 times. The modified soy flour additive-treated pulp sheets had significantly increased water repellency, gloss, and reduced roughness. Finally, decomposition of both modified and unmodified soy flour additives was studied under open-air conditions. The unmodified soy flour additive decomposed rapidly (within 24 hours) as indicated by its characteristically foul odor, an observation that did not hold for the modified soy flour additive that kept intact despite nearly two years of open-air exposure. The chemical and physical properties of the modified soy flour and modified soy flour additive-treated pulp sheets were characterized by FTIR, TGA, DSC, and contact angle measurements.}, booktitle={Soy-based chemicals and materials}, author={Salam, A. and Jameel, H. and Liu, Y. and Lucia, Lucian}, year={2014}, pages={255–264} }
 @article{naithani_jameel_banerjee_hart_lucia_2014, title={Potential contribution of anion exclusion to hydroxide penetration in green liquor-modified kraft pulping}, volume={68}, ISSN={["1437-434X"]}, DOI={10.1515/hf-2013-0208}, abstractNote={Abstract Partial substitution of green liquor for white liquor in kraft pulping reduces calcining energy and reportedly enhances product properties. However, a full-scale trial showed that pulper rejects increased when green liquor substitution levels approached 10%. Imaging experiments and laboratory pulping runs demonstrate that the slower diffusion of hydroxide in the presence of green liquor carbonate is likely responsible for the elevated rejects. Green liquor substitution becomes increasingly more viable with decreasing chip thickness. Hence, such an approach should be especially suited to sawdust pulping where diffusion is not rate determining.}, number={6}, journal={HOLZFORSCHUNG}, author={Naithani, Ved and Jameel, Hasan and Banerjee, Sujit and Hart, Peter W. and Lucia, Lucian A.}, year={2014}, month={Aug}, pages={617–621} }
 @article{li_li_hu_zu_wang_jameel_chang_2014, title={Pretreatment of corn stover for sugar production by a two-step process using dilute hydrochloric acid followed by aqueous ammonia}, volume={9}, DOI={10.15376/biores.9.3.4622-4635}, abstractNote={A novel two-step process for pretreatment of corn stover was investigated with the goal of increasing sugar recovery and decreasing the capital cost. In the process, corn stover was first treated with dilute hydrochloric acid to maximize xylan recovery, and then the residue was treated with aqueous ammonia to alter the lignin structure and swell the cellulose surface. The optimal conditions were 110 °C and 40 min for 1% dilute hydrochloric acid pretreatment with a liquid to solid ratio of 10:1 followed by aqueous ammonia pretreatment at 37% NH3, 130 °C, 30 min, and liquid to solid ratio of 6:1. Under these pretreatment conditions, the glucan and xylan recoveries were 83.2% and 97.3%, respectively, with cellulase dosage at 15 FPU/g of substrate. When the cellulase dosage was decreased from 15 FPU/g to 10 FPU/g of substrate, the glucan recovery only dropped to 70%, while the xylan recovery remained high at 95.1%. The results show that this two-step pretreatment was effective for achieving high sugar recovery from corn stover by enzymatic hydrolysis.}, number={3}, journal={BioResources}, author={Li, Z. H. and Li, W. Z. and Hu, H. P. and Zu, S. and Wang, Z. Y. and Jameel, H. and Chang, H. M.}, year={2014}, pages={4622–4635} }
 @article{zu_li_zhang_li_wang_jameel_chang_2014, title={Pretreatment of corn stover for sugar production using dilute hydrochloric acid followed by lime}, volume={152}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2013.11.034}, abstractNote={In this study, a two stage process was evaluated to increase the sugar recovery. Firstly, corn stover was treated with diluted hydrochloric acid to maximize the xylose yield, and then the residue was treated with lime to alter the lignin structure and swell the cellulose surface. The optimal condition was 120 °C and 40 min for diluted hydrochloric acid pretreatment followed by lime pretreatment at 60 °C for 12h with lime loading at 0.1 g/g of substrate. The glucose and xylose yield was 78.0% and 97.0%, respectively, with cellulase dosage at 5 FPU/g of substrate. The total glucose yield increased to 85.9% when the cellulase loading was increased to 10 FPU/g of substrate. This two stage process was effective due to the swelling of the internal surface, an increase in the porosity and a decrease in the degree of polymerization.}, journal={BIORESOURCE TECHNOLOGY}, author={Zu, Shuai and Li, Wen-zhi and Zhang, Mingjian and Li, Zihong and Wang, Ziyu and Jameel, Hasan and Chang, Hou-min}, year={2014}, month={Jan}, pages={364–370} }
 @article{andrade_colodette_oliveira_jardim_jameel_2014, title={Production of printing and writing paper grade pulp of sugar cane bagasse}, volume={13}, number={6}, journal={TAPPI Journal}, author={Andrade, M. F. and Colodette, J. L. and Oliveira, R. C. and Jardim, C. M. and Jameel, H.}, year={2014}, pages={35–44} }
 @article{wu_jameel_chang_phillips_2014, title={Techno-economic analysis of the optimum softwood lignin content for the production of bioethanol in a repurposed kraft mill}, volume={9}, DOI={10.15376/biores.9.4.6817-6830}, abstractNote={Kraft pulping is one possible pretreatment for softwood to economically produce bioethanol. This work evaluates the techno-economic potential of using the kraft process for producing bioethanol from softwoods in a repurposed or co-located kraft mill. Pretreated loblolly pine was enzymatically hydrolyzed at low enzyme dosages of 5 and 10 FPU/g of substrate. Pretreated residue with 13% lignin content had the highest sugar recovery, 32.7% and 47.7% at 5 and 10 FPU/g, respectively. The pretreated residues were oxygen delignified and refined. In all cases, oxygen delignification improved sugar recovery, while refining was mostly effective for pulps with high lignin content. At 5 FPU/g, the sugar recovery for all kraft pulps was 51 to 53% with oxygen delignification and refining. Increasing the enzyme dosage to 10 FPU/g increased the sugar recovery for these pulps to greater than 60%. Economic analysis for the pulps with different initial lignin content showed that kraft pulps with an initial lignin content of 6.7% with oxygen delignification had an ethanol yield of 285 L/ODt wood and the lowest total production cost of $0.55/L. Pulps with initial lignin content of 18.6% had a total production cost of $0.64/L with an ethanol yield of 264 L/ODt wood.}, number={4}, journal={BioResources}, author={Wu, S. F. and Jameel, H. and Chang, H. M. and Phillips, R.}, year={2014}, pages={6817–6830} }
 @article{min_yang_chiang_jameel_chang_2014, title={The influence of lignin-carbohydrate complexes on the cellulase-mediated saccharification II: Transgenic hybrid poplars (Populus nigra L. and Populus maximowiczii A.)}, volume={116}, ISSN={["1873-7153"]}, DOI={10.1016/j.fuel.2013.07.046}, abstractNote={Twelve transgenic hybrid poplars (Populus nigra L. and Populus maximowiczii A.) were used to demonstrate the influence of the lignin–carbohydrate complexes (LCCs) on enzymatic saccharification. The samples have different levels of the syringaldehyde (S) to vanillin (V) ratio from 0.1 to 2.6 and the lignin content from 10.5% to 24.3%, compared to the control (the S/V ratio 1.7 and the lignin content 22.0%). Any adventitious contaminants that could affect the final enzymatic saccharification were removed by performing thorough extraction on the samples. The crude milled wood lignins were subsequently isolated from which the phenyl glycoside, benzyl ether and γ-ester linkages representative of the LCC were identified and quantified by 13C and 1H–13C HSQC NMR. It was found that the samples showed different levels of the three LCC linkages, depending on the lignin content and/or the S/V ratio. The correlation between the LCCs and enzymatic saccharification nearly conclusively demonstrated that the LCCs accounted for the recalcitrance of lignocellulosic biodegradation.}, journal={FUEL}, author={Min, Dou-yong and Yang, Chenmin and Chiang, Vincent and Jameel, Hasan and Chang, Hou-min}, year={2014}, month={Jan}, pages={56–62} }
 @article{min_jameel_chang_lucia_wang_jin_2014, title={The structural changes of lignin and lignin-carbohydrate complexes in corn stover induced by mild sodium hydroxide treatment}, volume={4}, ISSN={["2046-2069"]}, DOI={10.1039/c3ra47032f}, abstractNote={Non-woody biomass such as corn stover is a very abundant and sustainable biofuel feedstock in the US whose technical hurdles for enzymatic hydrolysis have not been adequately addressed. There is very little useful data on the lignin and the lignin–carbohydrate complexes of corn stover and the impacts of them on bioconversion to fermentable sugars. The following principal tasks were addressed, which will help to develop the roadmap of effective saccharification of corn stover: (1) corn stover was separated into stem, cob, and leaf; (2) lignin (cellulolytic enzyme lignin, CEL) and lignin–carbohydrate complexes (milled wood lignin, MWLc) were isolated from the extractive-free and the alkaline-treated samples, respectively; and (3) the structural changes of lignin and lignin–carbohydrate complexes (LCCs) were characterized by alkaline nitrobenzene oxidation, 13C, and 1H–13C HSQC NMR. The results indicated: (1) a significant amount of p-coumarate and ferulate esters was identified and quantified; (2) lignin of the alkaline-treated sample was more condensed; (3) an unanticipated amount of LCCs was quantified in the extractive-free sample, however, the amount of LCCs decreased significantly with the alkaline treatment. Therefore, lignin and LCCs of the treated sample should be characterized to elucidate their effects on the enzymatic saccharification.}, number={21}, journal={RSC ADVANCES}, author={Min, D. Y. and Jameel, H. and Chang, H. M. and Lucia, L. and Wang, Z. G. and Jin, Y. C.}, year={2014}, pages={10845–10850} }
 @article{min_chang_jameel_lucia_wang_jin_2014, title={The structure of lignin of corn stover and its changes induced by mild sodium hydroxide treatment}, volume={9}, DOI={10.15376/biores.9.2.2405-2414}, abstractNote={Corn stover is an abundant feedstock in the US that can be used for second generation bioethanol production. However, there is little useful data on structure of the lignin of corn stover. The following principal tasks will be addressed to profile the structure of corn stover: (1) separation of corn stover into stem, cob, and leaf; (2) isolation of cellulolytic enzyme lignins (CEL) from extractive-free and the alkali-treated fractions; (3) quantification of p-coumarate and ferulate of fractions by HPLC. The results of alkaline nitrobenzene oxidation and 1H-13C HSQC NMR indicated: (1) the structure of lignin varied in the fractions; (2) a remarkable amount of p-coumarate and ferulate was identified and determined; (3) the remarkable structural changes of lignin induced by alkaline treatment were elucidated.}, number={2}, journal={BioResources}, author={Min, D. Y. and Chang, H. M. and Jameel, H. and Lucia, Lucian and Wang, Z. G. and Jin, Y. C.}, year={2014}, pages={2405–2414} }
 @article{min_li_chiang_jameel_chang_lucia_2014, title={nnThe influence of lignin-carbohydrate complexes on the cellulase-mediated saccharification I: Transgenic black cottonwood (western balsam poplar, California poplar) P-trichocarpa including the xylan down-regulated and the lignin down-regulated lines}, volume={119}, ISSN={["1873-7153"]}, DOI={10.1016/j.fuel.2013.11.047}, abstractNote={The influence of the putative lignin–carbohydrate complexes (LCCs) on enzymatic saccharification was elucidated for the first time by examining two groups of transgenic black cottonwood (P. trichocarpa) comprised of the lignin down-regulated and the xylan down-regulated lines. Any adventitious contaminants that could affect the characterization of LCCs and the enzymatic saccharification were removed by performing a thorough extraction on the samples. The crude milled wood lignin was subsequently isolated from which the phenyl glycoside, benzyl ether and γ-ester linkages representative of the LCCs were identified and quantified with the combination of 13C and 1H–13C Heteronuclear Single Quantum Coherence (HSQC) NMR. The result indicated that the samples showed different levels of the three LCC linkages, depending on the xylan and/or lignin content. The correlation between the LCCs and enzymatic saccharification nearly conclusively demonstrated that the LCCs accounting for the recalcitrance of lignocellulosic biodegradation.}, journal={FUEL}, author={Min, Dou-yong and Li, Quanzi and Chiang, Vincent and Jameel, Hasan and Chang, Hou-min and Lucia, Lucian}, year={2014}, month={Mar}, pages={207–213} }
 @article{salam_lucia_jameel_2013, title={A Novel Cellulose Nanocrystals-Based Approach To Improve the Mechanical Properties of Recycled Paper}, volume={1}, ISSN={["2168-0485"]}, DOI={10.1021/sc400226m}, abstractNote={The ability to introduce cellulose nanocrystals (CNs) into any of a number of single-component or composite applications is currently limited because they are difficult to efficiently isolate and in certain cases difficult to maintain homogeneously disperse. The current research introduces a novel purification technique and composite application for modified cellulose nanocrystal derivatives by using them as an additive for dry strength in recycled paper OCC (old corrugated containerboard). More specifically, the present work illustrates a way to easily isolate CNs by extracting them through a traditional mineral acid hydrolysis followed up by washing them several times with ethanol. The extracted cellulose nanocrystals did not flocculate and were completely homogeneously dispersed in water. Additionally, it was found that the incorporation of carboxylic acid functionalities onto the CNs by reaction with diethylenetriamine pentaacetic acid (DTPA) followed by cross-linking with chitosan and introduction in...}, number={12}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Salam, Abdus and Lucia, Lucian A. and Jameel, Hasan}, year={2013}, month={Dec}, pages={1584–1592} }
 @article{chi_chang_li_jameel_zhang_2013, title={A method for rapid determination of sugars in lignocellulose prehydrolyzate}, volume={8}, DOI={10.15376/biores.8.1.172-181}, abstractNote={A simple and rapid dual-wavelength spectroscopic method is used for simultaneous determination of pentoses and hexoses in the prehydrolyzate from lignocellulosic biomass. The method is based on the following reaction mechanism: in the solution of hydrochloric acid, phloroglucinol gives color reaction with sugars or their degradation products, showing maximum absorbance at 553 nm and 410 nm. Based on dual-wavelength spectrophotometric measurement, the pentoses and hexoses can separately be quantified. It was found that the derivatives from these two different sugars have an isosbestic point at 425 nm. According to the validation results, high accuracy and reasonable recovery rate is shown with the present method (pentoses recovery 97.1 to 100.0%, hexoses recovery 97.2 to 102.0%). Additionally, the interferences from substances including lignin, furfural, 5-hydroxymethyl furfural (HMF), glucuronic acid, and galacturonic acid are insignificant. All of the above results illustrate the suitability of this method for analyzing sugars in the lignocelluloses prehydrolyzate, especially hardwoods or herbaceous plants, based on forest-related biorefinery research.}, number={1}, journal={BioResources}, author={Chi, C. C. and Chang, H. M. and Li, Z. J. and Jameel, H. and Zhang, Z.}, year={2013}, pages={172–181} }
 @article{ayoub_venditti_jameel_chang_2013, title={Effect of irradiation on the composition and thermal properties of softwood kraft lignin and styrene grafted lignin}, volume={131}, ISSN={0021-8995}, url={http://dx.doi.org/10.1002/APP.39743}, DOI={10.1002/app.39743}, abstractNote={Lignin is an abundant, underutilized natural resource that has potential to be used as a biomaterial but is currently hampered in its use by not being uniform in structure and composition and is thermally unstable due to phenolic group. To address these issues and modify its thermal properties, softwood kraft lignin was modified using γ-irradiation at low doses with and without styrene present and characterized. Irradiation of kraft lignin alone with γ-radiation shows an initial decrease in molecular weight due to chain scission up to about 10 kGy followed by an increase in molecular weight due to crosslinking. NMR results indicate a decrease of about 15% in the OH content of the lignin with 30 kGy irradiation. Thermal properties such as Tg, free volume and ΔCp follow accordingly. Irradiation at very low dosages was determined to facilitate the grafting of styrene monomer to lignin, decreasing the OH content by 23%. This effect increased the hydrophobicity of the material, depressed the value of Tg, increased the ΔCp, increased the mobility in the liquid state, and made the material more thermally stable relative to the lignin alone, thus improving its processability at high temperatures. Both the irradiation of lignin alone and the grafting of styrene to lignin increased the yield of mass during pyrolysis and the activation energy for mass loss relative to untreated lignin alone. This work has demonstrated that the application of low dosages of γ-irradiation is a promising method to attach functional molecules onto lignin for use in various applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39743.}, number={1}, journal={Journal of Applied Polymer Science}, publisher={Wiley}, author={Ayoub, Ali and Venditti, Richard A. and Jameel, Hasan and Chang, Hou-Min}, year={2013}, month={Jul}, pages={n/a-n/a} }
 @article{jones_venditti_park_jameel_koo_2013, title={Enhancement in enzymatic hydrolysis by mechanical refining for pretreated hardwood lignocellulosics}, volume={147}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2013.08.030}, DOI={10.1016/j.biortech.2013.08.030}, abstractNote={This study investigated the effectiveness of mechanical refining to overcome the biomass recalcitrance barrier. Laboratory scale refining was conducted via PFI mill and valley beater refiners using green liquor and Kraft hardwood pulps. A strong positive correlation was determined between sugar recovery and water retention value. Refining produced significant improvements in enzymatic hydrolysis yield relative to unrefined substrates (e.g., sugar recovery increase from 67% to 90%, for 15% lignin Kraft pulp). A maximum absolute enzymatic hydrolysis improvement with refining was observed at enzymatic hydrolysis conditions that produced intermediate conversion levels. For a 91% target sugar conversion, PFI refining at 4000 revolutions allowed for a 32% reduction in enzyme charge for 15% lignin content hardwood Kraft pulp and 96 h hydrolysis time, compared to the unrefined material.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Jones, Brandon W. and Venditti, Richard and Park, Sunkyu and Jameel, Hasan and Koo, Bonwook}, year={2013}, month={Nov}, pages={353–360} }
 @article{longue_ayoub_venditti_jameel_colodette_chang_2013, title={Ethanol precipitation of hetero-polysaccharide material from hardwood by alkaline extraction prior to the Kraft cooking process}, volume={8}, DOI={10.15376/biores.8.4.5319-5332}, abstractNote={Hemicellulose material is an abundant and relatively under-utilized hetero-polysaccharide material present in lignocellulosic materials. In this study, an alkaline treatment was applied to sweetgum and Eucalyptus globulus chips to extract hemicelluloses prior to kraft pulping to subsequently evaluate the final product and process. An alkaline extraction (10 and 50% NaOH by weight on wood) for 60 min at 100 °C followed by precipitation in ethanol recovered 4.3% of the biomass as a predominantly xylan material (sweetgum 50% NaOH) with an average degree of polymerization around 250 and functional groups similar to a commercial xylan (sweetgum 10% NaOH). This process in comparison to autohydrolysis (water extraction at 100 °C) produced a much higher molecular weight and more pure hemicellullose. The results obtained indicate a promising combination between the effective extraction of hemicellulose from wood and a distillation process that recovers the ethanol, which may be an attractive alternative to recover liquor and ethanol after hemicellulose precipitation. Hemicellulose from sweetgum showed more thermal stability with high molecular weight compared to the hemicellulose extracted from Eucalyptus globulus. An attractive alternative looks to be to recover liquor and ethanol after hemicellulose precipitation.}, number={4}, journal={BioResources}, author={Longue, D. and Ayoub, A. and Venditti, Richard and Jameel, H. and Colodette, J. L. and Chang, H. M.}, year={2013}, pages={5319–5332} }
 @article{santos_jameel_chang_hart_2013, title={Impact of lignin and carbohydrate chemical structures on degradation reactions during hardwood kraft pulping processes}, volume={8}, DOI={10.15376/biores.8.1.158-171}, abstractNote={Most studies aimed at determining rates of hardwood delignification and carbohydrate degradation have focused on understanding the behavior of a single wood species. Such studies tend to determine either the delignification rate or the rate of carbohydrate degradation without examining the potential interactions resulting from related variables. The current study provides a comprehensive evaluation on both lignin and carbohydrate degradation during kraft pulping of multiple hardwood species. The kraft delignification rates of E. urograndis, E. nitens, E. globulus, sweet gum, maple, red oak, red alder, cottonwood, and acacia were obtained. Furthermore, the kinetics of glucan, xylan, and total carbohydrate dissolution during the bulk phase of the kraft pulping process for the above species were also investigated. The wide ranges of delignification and carbohydrate degradation rates were correlated to wood chemical characteristics. It appears that the S/G ratio and lignin-carbohydrate-complexes (LCCs) are the main characteristics responsible for the differences in kraft pulping performance among the hardwoods studied.}, number={1}, journal={BioResources}, author={Santos, R. B. and Jameel, H. and Chang, H. M. and Hart, P. W.}, year={2013}, pages={158–171} }
 @article{daystar_venditti_gonzalez_jameel_jett_reeb_2013, title={Impacts of feedstock composition on alcohol yields and greenhouse gas emissions from the NREL thermochemical ethanol conversion process}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84887201884&partnerID=MN8TOARS}, DOI={10.15376/biores.8.4.5261-5278}, abstractNote={There has been great attention focused on the effects of first and second generation biofuels on global warming. The Energy Independence and Security Act (EISA) and the Renewable Fuel Standard (RFS) have mandated production levels and performance criteria of biofuels in the United States. The thermochemical conversion of biomass to ethanol shows potential as a biofuel production pathway. The objective of this research was to examine the alcohol yields and GHG emissions from the thermochemical conversion process for six different feedstocks on a gate-to-gate basis. GHG analyses and life cycle assessments were performed for natural hardwood, loblolly pine, eucalyptus, miscanthus, corn stover, and switchgrass feedstocks using a NREL thermochemical model and SimaPro. Alcohol yield and GHG emission for the hybrid poplar baseline feedstock conversion were 105,400 L dry metric ton−1 and 2.8 kg CO2 eq. per liter, respectively. Compared with the baseline, loblolly pine produced the highest alcohol yields, an 8.5% increase, and the lowest GHG emissions per liter of ethanol, a 9.1% decrease. Corn stover, due to its high ash content, had the lowest yields and the highest GHG emissions per liter of ethanol. The results were highly sensitive to the ash and water content of the biomass, indicating that biomass properties can significantly affect the environmental impact of the thermochemical ethanol conversion process.}, number={4}, journal={BioResources}, author={Daystar, J. S. and Venditti, Richard and Gonzalez, R. and Jameel, H. and Jett, M. and Reeb, C. W.}, year={2013}, pages={5261–5278} }
 @article{min_smith_chang_jameel_2013, title={Influence of isolation condition on structure of milled wood lignin characterized by quantitative c-13 nuclear magnetic resonance spectroscopy}, volume={8}, DOI={10.15376/biores.8.2.1790-1800}, abstractNote={Milled wood lignin (MWL) was widely characterized to demonstrate the structure of native lignin by liquid state 13C NMR. As an isolated lignin, the structure of MWL was influenced by the isolation procedure performed. In this article, hardwood (sweetgum) and softwood (loblolly pine) were subjected to various isolation conditions to elucidate the effect of extracting temperature and milling time on the structure of MWL. Purification was also carried out on the crude MWL. The structure of the crude MWL and the purified MWL was identified and quantified by 13C NMR. Based on the yield and the lignin content of the crude MWL, the optimal isolation was achieved with 8 h milling and 20 °C extracting for hardwood. For softwood, the optimal isolation condition for crude MWL was 12 h milling and 20 °C extracting.}, number={2}, journal={BioResources}, author={Min, D. Y. and Smith, S. W. and Chang, H. M. and Jameel, H.}, year={2013}, pages={1790–1800} }
 @article{phillips_jameel_chang_2013, title={Integration of pulp and paper technology with bioethanol production}, volume={6}, ISSN={["1754-6834"]}, DOI={10.1186/1754-6834-6-13}, abstractNote={Despite decades of work and billions of dollars of investments in laboratory and pilot plant projects, commercial production of cellulosic ethanol is only now beginning to emerge. Because of: (1)high technical risk coupled with; (2) high capital investment cost relative to ethanol product value, investors have not been able to justify moving forward with large scale projects on woody biomass.Both issues have been addressed by targeting pulp and paper industry processes for application in bioethanol production, in Greenfield, Repurpose and Co-Location scenarios. Processes commercially proven in hundreds of mills for many decades have been tailored to the recalcitrance of the biomass available. Economically feasible cellulosic bioethanol can be produced in Greenfield application with hardwoods, but not softwoods, using kraft mill equipment. Both types of wood species can profitably produce ethanol when kraft mill or newsprint assets are Repurposed to a biorefinery. A third situation which can generate high financial returns is where excess kraft pulp is available at a mill which has no excess drying capacity. Each scenario is supported by laboratory simulation, engineering and financial analysis. While pretreatment is critical to providing access of the biomass to enzymes, capital investment per unit of ethanol produced can be attractive, even if ethanol yield is modest.Three guiding principles result in attractive economics: (1) re-use existing assets to the maximum extent; (2) keep the process as simple as possible; (3) match the recalcitrance of the biomass with the severity of the pretreatment.}, journal={BIOTECHNOLOGY FOR BIOFUELS}, author={Phillips, Richard B. and Jameel, Hasan and Chang, Hou Min}, year={2013}, month={Jan} }
 @article{yu_jameel_chang_philips_park_2013, title={Quantification of bound and free enzymes during enzymatic hydrolysis and their reactivities on cellulose and lignocellulose}, volume={147}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2013.08.010}, DOI={10.1016/j.biortech.2013.08.010}, abstractNote={Enzymatic hydrolysis of insoluble biomass is a surface reaction. Part of the enzyme adsorb on the surface of biomass, whereas the others stay in the liquid phase. In this study, three substrates (Avicel cellulose, bleached hardwood pulp, and green-liquor pretreated hardwood pulp) were used to study the reactivity of bound and free enzyme. In a continuous enzymatic hydrolysis, 35-65% initially added enzymes became bound enzymes, which were primarily responsible for enzymatic hydrolysis. The contribution from free enzymes became insignificant after a certain period of reaction time. SDS-PAGE analysis showed that CBH I was significantly decreased in the free enzyme, which might be the reason for the low digestibility of free enzymes due to the loss of synergistic effect. When Tween 80 was added during enzymatic hydrolysis, the digestibility of free enzyme on Avicel was greatly enhanced. However, the benefit of surfactant was not noticeable for lignocellulosic pulps, comparing to Avicel.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Yu, Zhiying and Jameel, Hasan and Chang, Hou-min and Philips, Richard and Park, Sunkyu}, year={2013}, month={Nov}, pages={369–377} }
 @article{jin_yang_jameel_chang_phillips_2013, title={Sodium sulfite-formaldehyde pretreatment of mixed hardwoods and its effect on enzymatic hydrolysis}, volume={135}, ISSN={["0960-8524"]}, DOI={10.1016/j.biortech.2012.09.073}, abstractNote={In this work, mixed hardwoods were pretreated by sodium sulfite-formaldehyde (SF). The effects of SF pretreatment on the chemical compositions and enzymatic hydrolysis of mixed hardwoods were investigated. SF pretreatment temperature had a significant effect on pulp yield and delignification, resulting in an increased efficiency of enzymatic hydrolysis. After 96 h of enzymatic hydrolysis at the cellulase loading of 40 FPU/g substrate, the yields of glucan and xylan on the basis of original wood were 37% and 11% for the pulp produced with 12% sulfite charge at 170 °C for 2 h. The total sugar recovery based on the sugar in original wood was 74%. These results indicate that sulfite-formaldehyde cooking is of great potential to be a pretreatment method for a greenfield mill to produce fuel ethanol from hardwood.}, journal={BIORESOURCE TECHNOLOGY}, author={Jin, Yongcan and Yang, Linfeng and Jameel, Hasan and Chang, Hou-min and Phillips, Richard}, year={2013}, month={May}, pages={109–115} }
 @article{salam_lucia_jameel_2013, title={Synthesis, Characterization, and Evaluation of Chitosan-Complexed Starch Nanoparticles on the Physical Properties of Recycled Paper Furnish}, volume={5}, ISSN={["1944-8252"]}, DOI={10.1021/am403261d}, abstractNote={The objectives of the current research were to synthesize and characterize chitosan-complexed starch nanoparticles and examine their effect on the physical performance of recycled pulp, specifically old corrugated containerboard (OCC). This new approach provides a uniquely renewable and useful approach to enhance mechanical properties of pulp while maintaining environmental compatibility, industrial compatibility, and paper qualities. The starch nanoparticles used for the research were prepared from cooked cornstarch gel with ethanol and reacted with diethylenetriamine pentaacetic acid (DTPA) in the presence of sodium hypophosphite. Thereupon, the DTPA-modified starch nanoparticles (SNs) were complexed with chitosan as part of a general chemical strategy to improve their incorporation into an OCC matrix and increase interfiber bonding. Spectral characterization of the SNs was done using TGA, DSC, FT-IR, and SEM to analyze their composition and structure. Approximately 2% chitosan-complexed starch nanoparticle derivatives by mass (SNX/C) of OCC-based slurry were thoroughly mixed before manufacturing a two-dimensional sheet for physical testing. The tensile and burst strength of the modified OCC pulp sheet increased 50 and 49%, respectively, albeit having a decreased tear strength compared to the control sample. However, when the OCC pulp sheet was coated with a 1% SNX/C by mass solution, the tensile and burst strength increased 120 and 70%, respectively, while also providing significantly increased gloss, decreased roughness, and tear strength. Because the mechanical properties are the most critical property facing the recyclability of OCCs, the tremendous gains afforded by the starch nanoparticle-DTPA-chitosan proposed give the system enormous potential applicability as a viable dry strength agent for paper substrates.}, number={21}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Salam, Abdus and Lucia, Lucian A. and Jameel, Hasan}, year={2013}, month={Nov}, pages={11029–11037} }
 @article{min_yang_shi_jameel_chiang_chang_2013, title={The elucidation of the lignin structure effect on the cellulase-mediated saccharification by genetic engineering poplars (Populus nigra L. x Populus maximowiczii A.)}, volume={58}, ISSN={["1873-2909"]}, DOI={10.1016/j.biombioe.2013.08.019}, abstractNote={The lignin structure effect on the recalcitrance of biomass degradation was elucidated by twelve transgenic hybrid poplars (Populus nigra L. and Populus maximowiczii A.). Samples have different levels of the syringaldehyde (S) to vanillin (V) ratio from 0.1 to 2.6 and the lignin content from 10.5 to 24.3%, compared to the control (the S to V ratio 1.7 and the lignin content 22.0%). The dilute acid (0.1% sulfuric acid, 185 °C, and 30 min) and the green liquor (6% total titratable alkali (TTA), 25% sulfidity based on TTA, 185 °C and 15 min) were used as pretreatments. The enzymatic saccharification was performed at 5 FPU g−1 based on the substrate. The removal of lignin and hemicelluloses varied with pretreatments. The high delignification originated from the high S to V ratio. However, the high S to V ratio retarded the enzymatic saccharification. The decrease of the lignin and the hemicelluloses benefited the enzymatic saccharification with or without the pretreatment.}, journal={BIOMASS & BIOENERGY}, author={Min, Douyong and Yang, Chenmin and Shi, Rui and Jameel, Hasan and Chiang, Vincent and Chang, Houmin}, year={2013}, month={Nov}, pages={52–57} }
 @article{santos_hart_jameel_chang_2013, title={Wood based lignin reactions important to the biorefinery and pulp and paper industries}, volume={8}, DOI={10.15376/biores.8.1.1456-1477}, abstractNote={The cleavage of lignin bonds in a wood matrix is an important step in the processes employed in both the biorefinery and pulp and paper industries. β-O-4 ether linkages are susceptible to both acidic and alkaline hydrolysis. The cleavage of α-ether linkages rapidly occurs under mildly acidic reaction conditions, resulting in lower molecular weight lignin fragments. Acidic reactions are typically employed in the biorefinery industries, while alkaline reactions are more typically employed in the pulp and paper industries, especially in the kraft pulping process. By better understanding lignin reactions and reaction conditions, it may be possible to improve silvicultural and breeding programs to enhance the formation of easily removable lignin, as opposed to more chemically resistant lignin structures. In hardwood species, the S/G ratio has been successfully correlated to the amount of β-O-4 ether linkages present in the lignin and the ease of pulping reactions.}, number={1}, journal={BioResources}, author={Santos, R. B. and Hart, P. W. and Jameel, H. and Chang, H. M.}, year={2013}, pages={1456–1477} }
 @article{treasure_gonzalez_venditti_pu_jameel_kelley_prestemon_2012, title={Co-production of electricity and ethanol, process economics of value prior combustion}, volume={62}, ISSN={0196-8904}, url={http://dx.doi.org/10.1016/j.enconman.2012.04.002}, DOI={10.1016/j.enconman.2012.04.002}, abstractNote={A process economic analysis of co-producing bioethanol and electricity (value prior to combustion) from mixed southern hardwood and southern yellow pine is presented. Bioethanol is produced by extracting carbohydrates from wood via autohydrolysis, membrane separation of byproducts, enzymatic hydrolysis of extracted oligomers and fermentation to ethanol. The residual solids after autohydrolysis are pressed and burned in a power boiler to generate steam and electricity. A base case scenario of biomass combustion to produce electricity is presented as a reference to understand the basics of bio-power generation economics. For the base case, minimum electricity revenue of $70–$96/MWh must be realized to achieve a 6–12% internal rate of return. In the alternative co-production cases, the ethanol facility is treated as a separate business entity that purchases power and steam from the biomass power plant. Minimum ethanol revenue required to achieve a 12% internal rate of return was estimated to be $0.84–$1.05/l for hardwood and $0.74–$0.85/l for softwood. Based on current market conditions and an assumed future ethanol selling price of $0.65/l, the co-production of cellulosic bioethanol and power does not produce financeable returns. A risk analysis indicates that there is a probability of 26.6% to achieve an internal rate of return equal or higher than 12%. It is suggested that focus be placed on improving yield and reducing CAPEX before this technology can be applied commercially. This modeling approach is a robust method to evaluate economic feasibility of integrated production of bio-power and other products based on extracted hemicellulose.}, journal={Energy Conversion and Management}, publisher={Elsevier BV}, author={Treasure, T. and Gonzalez, R. and Venditti, R. and Pu, Y. and Jameel, H. and Kelley, S. and Prestemon, Jeffrey}, year={2012}, month={Oct}, pages={141–153} }
 @article{gonzalez_daystar_jett_treasure_jameel_venditti_phillips_2012, title={Economics of cellulosic ethanol production in a thermochemical pathway for softwood, hardwood, corn stover and switchgrass}, volume={94}, ISSN={0378-3820}, url={http://dx.doi.org/10.1016/j.fuproc.2011.10.003}, DOI={10.1016/j.fuproc.2011.10.003}, abstractNote={The economics of producing cellulosic ethanol using loblolly pine, natural mixed hardwood, Eucalyptus, corn stover, and switchgrass as feedstocks was simulated in Aspen Plus using the thermochemical process via indirect gasification and mixed alcohol synthesis developed by NREL. Outputs from the simulation were linked to an economic analysis spreadsheet to estimate NPV, IRR, payback and to run further sensitivity analysis of the different combinations of feedstocks. Results indicate that forest-based feedstocks including loblolly pine, natural hardwood and eucalyptus may present more attractive financial returns when compared to switchgrass and corn stover, mainly due to their composition (%C, %H, %ash) and alcohol yield. Simulated alcohol yields from forest-based feedstock were significantly higher than from switchgrass and corn stover. Simulations run with switchgrass and corn stover, also demonstrated greater sensitivity to changes in ethanol price, alcohol yield, capital investment and biomass costs. Furthermore, moisture content of receiving feedstocks greatly affected the economics of the biorefinery. A difference of − 10% in the moisture content of the receiving feedstock affected the NPV of the simulated project by + 25% (with respect to central NPV of ~$192 million).}, number={1}, journal={Fuel Processing Technology}, publisher={Elsevier BV}, author={Gonzalez, R. and Daystar, J. and Jett, M. and Treasure, T. and Jameel, H. and Venditti, R. and Phillips, R.}, year={2012}, month={Feb}, pages={113–122} }
 @article{wu_chang_jameel_philips_2012, title={Effect of Additives on Polysaccharide Retention in Green Liquor Pretreatment of Loblolly Pine for Enzymatic Hydrolysis}, volume={32}, ISSN={["1532-2319"]}, DOI={10.1080/02773813.2012.678959}, abstractNote={Abstract In order to improve polysaccharide retention during pretreatment and increase enzymatic hydrolysis efficiency, green liquor (GL) pretreatment was performed at: (1) higher GL sulfidity; (2) higher sulfidity with the addition of sodium polysulfide; (3) higher sulfidity with the addition of sodium borohydride; or (4) higher sulfudity with the addition of sodium tetraborate. The results indicate that green liquor pretreatment with the higher sulfidity, with the addition of polysulfide and with the addition of sodium borohydride, is effective in increasing enzymatic conversion of the pretreated pulps. The addition of sodium tetraborate, on the other hand, is not effective. These measures can be combined with oxygen delignification and/or mechanical refining to further improve the enzymatic hydrolysis efficiency. Up to 80% of the polysaccharides in softwood can be converted to fermentable sugars, but only with the addition of 40 FPU enzyme dose.}, number={4}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Wu, Shu-Fang and Chang, Hou-Min and Jameel, Hasan and Philips, Richard}, year={2012}, pages={317–327} }
 @article{santos_lee_jameel_chang_lucia_2012, title={Effects of hardwood structural and chemical characteristics on enzymatic hydrolysis for biofuel production}, volume={110}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2012.01.085}, DOI={10.1016/j.biortech.2012.01.085}, abstractNote={This study investigated the influence of various hardwood characteristics on enzymatic hydrolysis. Important hardwood species, including three Eucalyptus species, were comprehensively characterized using quantitative 13C NMR, image analysis and fiber quality analysis. Hydrolysis efficiency from all the hardwoods was correlated to the wood chemical composition and lignin characteristics. Among the key wood components that control enzymatic hydrolysis efficiency, lignin content, enzyme adsorption on substrate and, the ratio of syringyl/guaiacyl (S/G) of the pretreated feedstock were identified as the most important. No wood morphological feature was found to have a significant influence on enzymatic conversion of the pretreated samples.}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Santos, Ricardo B. and Lee, Jung Myoung and Jameel, Hasan and Chang, Hou-Min and Lucia, Lucian A.}, year={2012}, month={Apr}, pages={232–238} }
 @article{yang_cao_jin_chang_jameel_phillips_li_2012, title={Effects of sodium carbonate pretreatment on the chemical compositions and enzymatic saccharification of rice straw}, volume={124}, ISSN={["0960-8524"]}, DOI={10.1016/j.biortech.2012.08.041}, abstractNote={The effects of sodium carbonate (Na2CO3) pretreatment on the chemical compositions and enzymatic saccharification of rice straw were investigated. The enzymatic digestibility of rice straw is enhanced after pretreatment since pretreated solids show significant delignification with high sugar availability. During pretreatment, an increasing temperature and Na2CO3 charge leads to enhanced delignification, whereas an increased degradation of polysaccharides as well, of which xylan acts more susceptible than glucan. The sugar recovery of enzymatic hydrolysis goes up rapidly with the total titratable alkali (TTA) increasing from 0% to 8%, and then it reaches a plateau. The highest sugar recovery of rice straw after pretreatment, 71.7%, 73.2%, and 76.1% for total sugar, glucan, and xylan, respectively, is obtained at 140 °C, TTA 8% and cellulase loading of 20 FPU/g-cellulose. In this condition, the corresponding delignification ratio of pretreated solid is 41.8%, while 95% of glucan and 76% of xylan are conserved.}, journal={BIORESOURCE TECHNOLOGY}, author={Yang, Linfeng and Cao, Jie and Jin, Yongcan and Chang, Hou-min and Jameel, Hasan and Phillips, Richard and Li, Zhongzheng}, year={2012}, month={Nov}, pages={283–291} }
 @article{chen_venditti_jameel_park_2012, title={Enzymatic Hydrolysis of Recovered Office Printing Paper with Low Enzyme Dosages to Produce Fermentable Sugars}, volume={166}, ISSN={0273-2289 1559-0291}, url={http://dx.doi.org/10.1007/s12010-011-9498-2}, DOI={10.1007/s12010-011-9498-2}, number={5}, journal={Applied Biochemistry and Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Chen, Hui and Venditti, Richard A. and Jameel, Hasan and Park, Sunkyu}, year={2012}, month={Jan}, pages={1121–1136} }
 @article{yu_jameel_chang_philips_park_2012, title={Evaluation of the factors affecting avicel reactivity using multi-stage enzymatic hydrolysis}, volume={109}, DOI={10.1002/bit.24386}, abstractNote={Multi‐stage and single‐stage enzymatic hydrolysis of cellulose (Avicel PH‐101) were conducted to investigate individual factors that affect the rate‐reducing kinetics of enzymatic hydrolysis. Understanding factors affecting enzymatic hydrolysis of Avicel will help improve hydrolysis of various biomasses. Product inhibition, enzyme deactivation, and the changes of substrate are potential factors that can affect the hydrolysis efficiency of Avicel. Multi‐stage enzymatic hydrolysis resulted in 36.9% and 25.4% higher carbohydrate conversion as compared to a single‐stage enzymatic hydrolysis with an enzyme loading of 5 and 20 FPU/g in a 96 h reaction. However, a decline in carbohydrate conversion of 1.6% and 2.6% was observed through each stage with 5 and 20 FPU/g, respectively. This indicated that the substrate became more recalcitrant as hydrolysis progressed. The decreased reactivity was not due to crystallinity because no significant change in crystallinity was detected by X‐ray diffraction. Product inhibition was significant at low enzyme loading, while it was marginal at high enzyme loading. Therefore, product inhibition can only partially explain this decreased conversion. Another important factor, enzyme deactivation, contributed to 20.3% and 25.4% decrease in the total carbohydrate conversion of 96 h hydrolysis with 5 and 20 FPU/g, respectively. This work shows that an important reason for the decreased Avicel digestibility is the effect of enzyme blockage, which refers to the enzymes that irreversibly adsorb on accessible sites of substrate. About 45.3% and 63.2% of the total decreased conversion at the end of the 8th stage with 5 and 20 FPU/g, respectively, was due to the presence of irreversibly adsorbed enzymes. This blockage of active sites by enzymes has been speculated by other researchers, but this article shows further evidence of this effect. Biotechnol. Bioeng. 2012; 109:1131–1139. © 2011 Wiley Periodicals, Inc.}, number={5}, journal={Biotechnology and Bioengineering}, author={Yu, Z. Y. and Jameel, H. and Chang, H. M. and Philips, R. and Park, Sunkyu}, year={2012}, pages={1131–1139} }
 @inproceedings{chen_gonzalez_phillips_venditti_jameel_park_2012, title={Exploring the potential of paper industry sludges for ethanol production}, booktitle={Proceeding of the 4th International Conference on Pulping, Papermaking and Biotechnology (ICPPB '12), vols. I and II}, author={Chen, H. and Gonzalez, R. and Phillips, R. and Venditti, R. and Jameel, H. and Park, S.}, year={2012}, pages={1040–1043} }
 @article{gu_yang_jin_han_chang_jameel_phillips_2012, title={Green liquor pretreatment for improving enzymatic hydrolysis of corn stover}, volume={124}, ISSN={["0960-8524"]}, DOI={10.1016/j.biortech.2012.08.054}, abstractNote={Green liquor consists of sodium carbonate and sodium sulfide and is readily available in any kraft mills. The green liquor pretreatment process for bioethanol production was developed for wood chips. This process uses only proven technology and equipment currently used in a kraft pulp mill and has several additional advantages such as high sugar recovery and concentration, no inhibitive substances produced, as compared to acid-based pretreatment methods. The liquor was used to pretreat corn stover for enhancing enzymatic hydrolysis in bioethanol production. Pulp yield of 70% with 45% lignin removal was achieved under optimized conditions (8% total titratable alkali, 40% sulfidity and 140 °C). About 70% of the original polysaccharides were converted into fermentable sugars, using 20 FPU/g-pulp of enzyme in the subsequent enzymatic hydrolysis. The result indicates that green liquor is a feasible pretreatment to improve the enzymatic saccharification of corn stover for bioethanol production.}, journal={BIORESOURCE TECHNOLOGY}, author={Gu, Feng and Yang, Linfeng and Jin, Yongcan and Han, Qiang and Chang, Hou-min and Jameel, Hasan and Phillips, Richard}, year={2012}, month={Nov}, pages={299–305} }
 @article{santos_treasure_gonzalez_phillips_lee_jameel_chang_2012, title={Impact of hardwood species on production cost of second generation ethanol}, volume={117}, ISSN={["1873-2976"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84861134453&partnerID=MN8TOARS}, DOI={10.1016/j.biortech.2012.04.083}, abstractNote={The present work targeted the understanding of the influence of nine different hardwood species as feedstock on ethanol production yield and costs. It was found that the minimum ethanol revenue (MER) ($ per gallon to the producer) to achieve a 12% internal rate of return (IRR) on invested capital was smaller for low lignin content samples and the influence of species characteristics remained restricted to high residual lignin content. We show that if the pretreatment being applied to the feedstock targets or is limited to low lignin removal, one can expect the species to have a significant impact on overall economics, playing important role to project success. This study also showed a variation of up to 40% in relative MER among hardwood species, where maple, globulus and sweet gum varied the least. Sensitivity analysis showed ethanol yield per ton of feedstock had the largest influence in MER, followed by CAPEX.}, journal={BIORESOURCE TECHNOLOGY}, author={Santos, Ricardo B. and Treasure, Trevor and Gonzalez, Ronalds and Phillips, Richard and Lee, Jung Myoung and Jameel, Hasan and Chang, Hou-min}, year={2012}, month={Aug}, pages={193–200} }
 @article{santos_jameel_chang_harts_2012, title={Kinetics of Hardwood Carbohydrate Degradation during Kraft Pulp Cooking}, volume={51}, ISSN={["0888-5885"]}, DOI={10.1021/ie301071n}, abstractNote={Most of the studies on hardwood carbohydrate degradation focus upon the understanding of carbohydrate behavior of a single wood species. These studies tend to determine the activation energies associated with the three different cooking phases and for the different reactions that participate in carbohydrate degradation. In the current study, a variety of hardwood species were comprehensively characterized and the kinetics of carbohydrate degradation was studied. The kinetics of glucan, xylan, and total carbohydrate dissolution during the bulk phase of the kraft pulping process were investigated. A wide range of carbohydrate dissolution rates was obtained and correlated to chemical features and delignification rates for nine different hardwood species. It was determined that carbohydrate dissolution was dependent upon the rate of delignification. Species with high carbohydrate dissolution also presented high lignin removal rates. Our results indicate that the presence of lignin carbohydrate complexes positively influences pulping process selectivity during the bulk reaction phase.}, number={38}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Santos, Ricardo B. and Jameel, Hasan and Chang, Hou-min and Harts, Peter W.}, year={2012}, month={Sep}, pages={12192–12198} }
 @article{santos_capanema_balakshin_chang_jameel_2012, title={Lignin Structural Variation in Hardwood Species}, volume={60}, ISSN={["1520-5118"]}, DOI={10.1021/jf301276a}, abstractNote={A comprehensive lignin structure analysis of ten industrially relevant hardwood species is presented. Milled wood lignin (MWL) was isolated from each species using a modified protocol and all milled wood lignin preparations were analyzed through quantitative (13)C NMR spectroscopy, elemental analysis, methoxyl analysis, sugar analysis, and nitrobenzene oxidation. Nitrobenzene oxidation and ozonation were carried out on extractive-free wood, alkali-extracted wood, milled wood lignin, and alkali-extracted lignin. Milled wood lignin isolated by the modified protocol was found to be representative of the total lignin in alkali-extracted wood. Significant variations in lignin structures, such as syringylpropane/guaiacylpropane ratio (S/G ratio), arylglycerol-β-aryl ether (β-O-4), degree of condensation, and elemental and methoxyl contents, were found among the hardwood species studied. These structural variations among species appear to be correlated to a single factor, the syringyl/guaiacyl ratio. A new method to predict the S/G ratio of total lignin in wood was developed, using a calibration line established by the syringaldehyde/vanillin (S/V) ratio (nitrobenzene oxidation) and the S/G ratio ((13)C NMR) of milled wood lignin (MWL).}, number={19}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Santos, Ricardo B. and Capanema, Ewellyn A. and Balakshin, Mikhail Yu and Chang, Hou-min and Jameel, Hasan}, year={2012}, month={May}, pages={4923–4930} }
 @article{xue_rusli_chang_phillips_jameel_2012, title={Process Evaluation of Enzymatic Hydrolysis with Filtrate Recycle for the Production of High Concentration Sugars}, volume={166}, ISSN={0273-2289 1559-0291}, url={http://dx.doi.org/10.1007/S12010-011-9474-X}, DOI={10.1007/S12010-011-9474-X}, abstractNote={Process simulation and lab trials were carried out to demonstrate and confirm the efficiency of the concept that recycling hydrolysate at low total solid enzymatic hydrolysis is one of the options to increase the sugar concentration without mixing problems. Higher sugar concentration can reduce the capital cost for fermentation and distillation because of smaller retention volume. Meanwhile, operation cost will also decrease for less operating volume and less energy required for distillation. With the computer simulation, time and efforts can be saved to achieve the steady state of recycling process, which is the scenario for industrial production. This paper, to the best of our knowledge, is the first paper discussing steady-state saccharification with recycling of the filtrate form enzymatic hydrolysis to increase sugar concentration. Recycled enzymes in the filtrate (15-30% of the original enzyme loading) resulted in 5-10% higher carbohydrate conversion compared to the case in which recycled enzymes were denatured. The recycled hydrolysate yielded 10% higher carbohydrate conversion compared to pure sugar simulated hydrolysate at the same enzyme loading, which indicated hydrolysis by-products could boost enzymatic hydrolysis. The high sugar concentration (pure sugar simulated) showed inhibition effect, since about 15% decrease in carbohydrate conversion was observed compared with the case with no sugar added. The overall effect of hydrolysate recycling at WinGEMS simulated steady-state conditions with 5% total solids was increasing the sugar concentration from 35 to 141 g/l, while the carbohydrate conversion was 2% higher for recycling at steady state (87%) compared with no recycling strategy (85%). Ten percent and 15% total solid processes were also evaluated in this study.}, number={4}, journal={Applied Biochemistry and Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Xue, Ying and Rusli, Jannov and Chang, Hou-min and Phillips, Richard and Jameel, Hasan}, year={2012}, month={Feb}, pages={839–855} }
 @article{silva_santos_jameel_colodette_lucia_2012, title={Quantitative Molecular Structure–Pyrolytic Energy Correlation for Hardwood Lignins}, volume={26}, ISSN={0887-0624 1520-5029}, url={http://dx.doi.org/10.1021/ef2014869}, DOI={10.1021/ef2014869}, abstractNote={The molecular structures of the milled wood lignins (MWLs) and technical lignins (TLs) obtained from four hardwood species (Eucalyptus urograndis, Eucalyptus nitens, Eucalyptus globulus, and Populus trichocarpa) were quantified by 13C nuclear magnetic resonance (NMR) in tandem with their thermal responses, as obtained by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Both MWLs and TLs showed similar DSC curves with two exothermic peaks (referred to as peaks 1 and 2). Also, maximum temperatures for MWL peaks were higher than for TL peaks, with an average of 20 and 10 °C for the first peak and second peak, respectively. Even though calculated enthalpies for MWLs were higher because of their purities, TLs had reasonable relationships between heat values and lignin substructures. TL had a positive correlation between condensed structures and the enthalpy value between 413 and 428 °C, but negative relationships were found at the latter temperature window for lignin substructures,...}, number={2}, journal={Energy & Fuels}, publisher={American Chemical Society (ACS)}, author={Silva, Teresa Cristina Fonseca and Santos, Ricardo Baillerini and Jameel, Hasan and Colodette, Jorge Luiz and Lucia, Lucian A.}, year={2012}, month={Feb}, pages={1315–1322} }
 @article{xue_jameel_phillips_chang_2012, title={Split addition cif enzymes in enzymatic hydrolysis at high solids concentration to increase sugar concentration for bioethanol production}, volume={18}, ISSN={["1876-794X"]}, DOI={10.1016/j.jiec.2011.11.132}, abstractNote={One challenge in making bioethanol production economical is to increase total solids in hydrolysis system while maintaining sugar conversion efficiency. Because the removal of excess water from hydrolysate requires enormous amounts of heat, large volume of reaction towers and high capital expenditure (CAPEX) for equipment, a lengthy operating time, and high operating costs. When solids loading in hydrolysis system increased from 5% to 20% with no mixing strategies, final sugar conversion decreased markedly. If cellulase is mixed with pulp at 5% solids and pressed to 20% solids, then 80% of the cellulase retained in the pulp thinned down the pulp mixture in 2 h. This thinning effect enabled additional cellulase, xylanase, and β-glucosidase to be mixed into the slurry. Sugar concentration was significantly improved; from 26 g/L to 121 g/L, while sugar conversion was remained as enzymatic hydrolysis with 5% total solids enzymatic hydrolysis. A US patent has been granted to NCSU for this concept and licenses have been granted to various companies.}, number={2}, journal={JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY}, author={Xue, Ying and Jameel, Hasan and Phillips, Richard and Chang, Hou-min}, year={2012}, month={Mar}, pages={707–714} }
 @article{xue_jameel_park_2012, title={Strategies to recycle enzymes and their impact on enzymatic hydrolysis for bioethanol production}, volume={7}, number={1}, journal={BioResources}, author={Xue, Y. and Jameel, H. and Park, S.}, year={2012}, pages={602–615} }
 @inproceedings{naithani_jameel_banerjee_hart_lucia_2012, title={The "CARBONATE EFFECT": AN IMPORTANT CONCEPT TO EXPLAIN THE EFFICIENCY OF GREEN LIQUOR-MODIFIED KRAFT PULPING}, booktitle={Proceeding of the 4th International Conference on Pulping, Papermaking and Biotechnology (ICPPB '12), vols. I and II}, author={Naithani, V. and Jameel, H. and Banerjee, S. and Hart, P. W. and Lucia, L. A.}, year={2012}, pages={411–413} }
 @article{min_li_jameel_chiang_chang_2012, title={The Cellulase-Mediated Saccharification on Wood Derived from Transgenic Low-Lignin Lines of Black Cottonwood (Populus trichocarpa)}, volume={168}, ISSN={["1559-0291"]}, DOI={10.1007/s12010-012-9833-2}, abstractNote={Downregulated lignin transgenic black cottonwood (Populus trichocarpa) was used to elucidate the effect of lignin and xylan content on enzymatic saccharification. The lignin contents of three transgenic samples (4CL1-1, 4CL1-4, and CH8-1-4) were 19.3, 16.7, and 15.0 %, respectively, as compared with the wild type (21.3 %). The four pretreatments were dilute acid (0.1 % sulfuric acid, 185 °C, 30 min), green liquor (6 % total titratable alkali, 25 % sulfidity based on TTA, 185 °C, and 15 min.), autohydrolysis (185 °C, 30 min), and ozone delignification (25 °C, 30 min). Following the pretreatment, enzymatic saccharification was carried out using an enzyme charge of 5 FPU/g of substrates. The removal of lignin and hemicellulose varies with both the types of pretreatments and the lignin content of the transgenic trees. Due to the greatest removal of lignin, green liquor induced the highest sugar production and saccharification efficiency, followed by acid, ozone, and autohydrolysis in descending order. The results indicated that lignin is the main recalcitrance of biomass degradation. At a given lignin content, pretreatment with ozone delignification had lower saccharification efficiency than the other pretreatment methods due to higher xylan content.}, number={4}, journal={APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY}, author={Min, Douyong and Li, Quanzi and Jameel, Hasan and Chiang, Vincent and Chang, Hou-min}, year={2012}, month={Oct}, pages={947–955} }
 @inproceedings{min_li_yang_chang_chiang_jameel_2012, title={The effects of transgenic samples on the enzymatic saccharification}, booktitle={Proceeding of the 4th International Conference on Pulping, Papermaking and Biotechnology (ICPPB '12), vols. I and II}, author={Min, D. Y. and Li, Q. Z. and Yang, C. M. and Chang, H. M. and Chiang, V. and Jameel, H.}, year={2012}, pages={1058–1062} }
 @inproceedings{yu_gwak_chang_park_jameel_2012, title={The impact of lignin on enzymatic hydrolysis of lignocellulosic biomass}, booktitle={Proceeding of the 4th International Conference on Pulping, Papermaking and Biotechnology (ICPPB '12), vols. I and II}, author={Yu, Z. Y. and Gwak, K. S. and Chang, H. M. and Park, S. and Jameel, H.}, year={2012}, pages={1143–1147} }
 @article{min_jameel_chiang_chang_2012, title={effect of lignin on enzymatic saccharification of hardwood after green liquor and sulfuric acid pretreatments}, volume={7}, DOI={10.15376/biores.7.2.2272-2283}, abstractNote={Red maple, sweet gum, trembling aspen, red alder, and Eucalyptus globulus samples were pretreated with dilute sulfuric acid and green liquor before enzymatic saccharification. Substrates showed different levels of delignification and sugar recovery, depending on the applied pretreatments and the syringaldehyde/vanillin ratio (S/V). Three major conclusions were drawn in this research. First, lignin is the greatest contributor to recalcitrance of hardwood to enzymatic saccharification. Second, a high S/V ratio is a useful indicator of high delignification during a pretreatment process. Third, green liquor pretreatment is a promising pretreatment method because of a high delignification degree and sugar recovery. In addition, xylan also contributes to the recalcitrance of hardwoods toward enzymatic saccharification.}, number={2}, journal={BioResources}, author={Min, D. Y. and Jameel, H. and Chiang, V. and Chang, H. M.}, year={2012}, pages={2272–2283} }
 @article{gonzalez_phillips_saloni_jameel_abt_pirraglia_wright_2011, title={Biomass to energy in the southern united states: supply chain and delivered cost}, volume={6}, number={3}, journal={BioResources}, author={Gonzalez, R. and Phillips, R. and Saloni, D. and Jameel, H. and Abt, R. and Pirraglia, A. and Wright, J.}, year={2011}, pages={2954–2976} }
 @article{min_li_jameel_chiang_chang_2011, title={Comparison of pretreatment protocols for cellulase-mediated saccharification of wood derived from transgenic low-xylan lines of cottonwood (P. trichocarpa)}, volume={35}, ISSN={["1873-2909"]}, DOI={10.1016/j.biombioe.2011.04.034}, abstractNote={The novel low xylan content transgenic cottonwood (P. trichocarpa) was used to elucidate recalcitrance of enzymatic saccharification with or without four different pretreatment methods. The xylan contents of two transgenic samples (8Di3 and 8Di5) were 11.4% and 11.7%, respectively, as compared with the wild type (16.0%). Contrarily, the lignin contents of two transgenic samples were 23.1% and 24.5%, respectively, as compared with the wild type (20.8%). The four pretreatments were dilute acid (0.1% sulfuric acid, 185 °C, 30 min), green liquor (6% total titratable alkali (TTA), 25% sulfidity based on TTA, 185 °C and 15 min), auto hydrolysis (185 °C, 30 min) and ozone delignification (25 °C, 30 min). Following the pretreatment, enzymatic saccharification was carried out using three enzyme charges of 10, 20 and 30 FPU per gram of substrate. The removal of lignin and hemicelluloses varied with the type of pretreatment and with the lignin content of the transgenic trees. High lignin content implied low enzymatic saccharification. Low xylan content native substrates lead to high enzymatic saccharification. High S to V (sryingaldehyde to vanillin) ratio substrates had high delignification during pretreatment. Compared to the wild type, the transgenics were better choice as feed stocks due to higher enzymatic saccharification without pretreatment which mean low the cost of bio-ethanol. Compared to three pretreatment methods, the green liquor pretreatment greatly improves the conversion of polysaccharides in general.}, number={8}, journal={BIOMASS & BIOENERGY}, author={Min, Douyong and Li, Quanzi and Jameel, Hasan and Chiang, Vincent and Chang, Hou-min}, year={2011}, month={Aug}, pages={3514–3521} }
 @article{gonzalez_treasure_phillips_jameel_saloni_abt_wright_2011, title={Converting Eucalyptus biomass into ethanol: Financial and sensitivity analysis in a co-current dilute acid process. Part II}, volume={35}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2010.10.025}, DOI={10.1016/j.biombioe.2010.10.025}, abstractNote={The technical and financial performance of high yield Eucalyptus biomass in a co-current dilute acid pretreatment followed by enzymatic hydrolysis process was simulated using WinGEMS® and Excel®. Average ethanol yield per dry Mg of Eucalyptus biomass was approximately 347.6 L of ethanol (with average carbohydrate content in the biomass around 66.1%) at a cost of $0.49 L−1 of ethanol, cash cost of ∼ $0.46 L−1 and CAPEX of $1.03 L−1 of ethanol. The main cost drivers are: biomass, enzyme, tax, fuel (gasoline), depreciation and labor. Profitability of the process is very sensitive to biomass cost, carbohydrate content (%) in biomass and enzyme cost. Biomass delivered cost was simulated and financially evaluated in Part I; here in Part II the conversion of this raw material into cellulosic ethanol using the dilute acid process is evaluated.}, number={2}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Gonzalez, R. and Treasure, T. and Phillips, R. and Jameel, H. and Saloni, D. and Abt, R. and Wright, J.}, year={2011}, month={Feb}, pages={767–772} }
 @article{lee_venditti_jameel_kenealy_2011, title={Detoxification of woody hydrolyzates with activated carbon for bioconversion to ethanol by the thermophilic anaerobic bacterium Thermoanaerobacterium saccharolyticum}, volume={35}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2010.10.021}, DOI={10.1016/j.biombioe.2010.10.021}, abstractNote={Autohydrolysis is a simple, green method of recovering sugars from biomass, using only hot water. One potential drawback is that byproducts are formed during the autohydrolysis process that could interfere with subsequent hydrolysis and fermentation to ethanol. In the present work, autohydrolysis prehydrolyzate from mixed hardwood chips was detoxified with activated carbon and the removal efficiency of byproducts as well as the loss of sugars determined. The resulting detoxified prehydrolyzate was evaluated for the fermentation to ethanol with a thermophilic anaerobic bacterium. Activated carbon at a 2.5 wt % level on the prehydrolyzate was able to remove 42% of formic acid, 14% of acetic acid, 96% of hydroxymethylfurfural (HMF) and 93% of the furfural. However, 8.9% of sugars were also removed. The removal of HMF and furfural follow expected adsorption isotherms but formic acid, acetic acid, and sugars did not. Autohydrolysis prehydrolyzates from mixed hardwood detoxified with activated carbon can be fermented with Thermoanaerobacterium saccharolyticum strain MO1442 with an essentially 100% yield. T. saccharolyticum strain MO1442 is able to metabolize the glucose, xylose, and arabinose in the hydrolyzate. The results showed the detoxification process with activated carbon improved the ethanol yields by the removal of toxic compounds, mainly HMF and furfural, with moderate loss of fermentable sugars.}, number={1}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Lee, Jung Myoung and Venditti, Richard A. and Jameel, Hasan and Kenealy, William R.}, year={2011}, month={Jan}, pages={626–636} }
 @article{li_min_wang_peszlen_horvath_horvath_nishimura_jameel_chang_chiang_2011, title={Down-regulation of glycosyltransferase 8D genes in Populus trichocarpa caused reduced mechanical strength and xylan content in wood}, volume={31}, ISSN={["1758-4469"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79953831391&partnerID=MN8TOARS}, DOI={10.1093/treephys/tpr008}, abstractNote={Members of glycosyltransferase protein families GT8, GT43 and GT47 are implicated in the biosynthesis of xylan in the secondary cell walls of Arabidopsis. The Arabidopsis mutant irx8 has a 60% reduction in xylan. However, over-expression of an ortholog of Arabidopsis IRX8, poplar PoGT8D, in Arabidopsis irx8 mutant could not restore xylan synthesis. The functions of tree GT8D genes remain unclear. We identified two GT8 gene homologs, PtrGT8D1 and PtrGT8D2, in Populus trichocarpa. They are the only two GT8D members and are abundantly and specifically expressed in the differentiating xylem of P. trichocarpa. PtrGT8D1 transcript abundance was >7 times that of PtrGT8D2. To elucidate the genetic function of GT8D in P. trichocarpa, the expression of PtrGT8D1 and PtrGT8D2 was simultaneously knocked down through RNAi. Four transgenic lines had 85-94% reduction in transcripts of PtrGT8D1 and PtrGT8D2, resulting in 29-36% reduction in stem wood xylan content. Xylan reduction had essentially no effect on cellulose quantity but caused an 11-25% increase in lignin. These transgenics exhibit a brittle wood phenotype, accompanied by increased vessel diameter and thinner fiber cell walls in stem xylem. Stem modulus of elasticity and modulus of rupture were reduced by 17-29% and 16-23%, respectively, and were positively correlated with xylan content but negatively correlated with lignin quantity. These results suggest that PtrGT8Ds play key roles in xylan biosynthesis in wood. Xylan may be a more important factor than lignin affecting the stiffness and fracture strength of wood.}, number={2}, journal={TREE PHYSIOLOGY}, publisher={Oxford University Press (OUP)}, author={Li, Quanzi and Min, Douyong and Wang, Jack Peng-Yu and Peszlen, Ilona and Horvath, Laszlo and Horvath, Balazs and Nishimura, Yufuko and Jameel, Hasan and Chang, Hou-Min and Chiang, Vincent L.}, year={2011}, month={Feb}, pages={226–236} }
 @article{gonzalez_treasure_phillips_jameel_saloni_2011, title={Economics of cellulosic ethanol production: Green liquor pretreatment for softwood and hardwood, greenfield and repurpose scenarios}, volume={6}, number={3}, journal={BioResources}, author={Gonzalez, R. and Treasure, T. and Phillips, R. and Jameel, H. and Saloni, D.}, year={2011}, pages={2551–2567} }
 @misc{santos_capanema_balakshin_chang_jameel_2011, title={Effect of hardwoods characteristics on kraft pulping process: Emphasis on lignin structure}, volume={6}, number={4}, journal={BioResources}, author={Santos, R. B. and Capanema, E. A. and Balakshin, M. Y. and Chang, H. M. and Jameel, H.}, year={2011}, pages={3623–3637} }
 @article{gonzalez_treasure_wright_saloni_phillips_abt_jameel_2011, title={Exploring the potential of Eucalyptus for energy production in the Southern United States: Financial analysis of delivered biomass. Part I}, volume={35}, ISSN={["0961-9534"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78650762982&partnerID=MN8TOARS}, DOI={10.1016/j.biombioe.2010.10.011}, abstractNote={Eucalyptus plantations in the Southern United States offer a viable feedstock for renewable bioenergy. Delivered cost of eucalypt biomass to a bioenergy facility was simulated in order to understand how key variables affect biomass delivered cost. Three production rates (16.8, 22.4 and 28.0 Mg ha−1 y−1, dry weight basis) in two investment scenarios were compared in terms of financial analysis, to evaluate the effect of productivity and land investment on the financial indicators of the project. Delivered cost of biomass was simulated to range from $55.1 to $66.1 per delivered Mg (with freight distance of 48.3 km from plantation to biorefinery) depending on site productivity (without considering land investment) at 6% IRR. When land investment was included in the analysis, delivered biomass cost increased to range from $65.0 to $79.4 per delivered Mg depending on site productivity at 6% IRR. Conversion into cellulosic ethanol might be promising with biomass delivered cost lower than $66 Mg−1. These delivered costs and investment analysis show that Eucalyptus plantations are a potential biomass source for bioenergy production for Southern U.S.}, number={2}, journal={BIOMASS & BIOENERGY}, author={Gonzalez, R. and Treasure, T. and Wright, J. and Saloni, D. and Phillips, R. and Abt, R. and Jameel, H.}, year={2011}, month={Feb}, pages={755–766} }
 @article{balakshin_capanema_gracz_chang_jameel_2011, title={Quantification of lignin-carbohydrate linkages with high-resolution NMR spectroscopy}, volume={233}, ISSN={["0032-0935"]}, DOI={10.1007/s00425-011-1359-2}, abstractNote={A quantitative approach to characterize lignin-carbohydrate complex (LCC) linkages using a combination of quantitative ¹³C NMR and HSQC 2D NMR techniques has been developed. Crude milled wood lignin (MWLc), LCC extracted from MWLc with acetic acid (LCC-AcOH) and cellulolytic enzyme lignin (CEL) preparations were isolated from loblolly pine (Pinus taeda) and white birch (Betula pendula) woods and characterized using this methodology on a routine 300 MHz NMR spectrometer and on a 950 MHz spectrometer equipped with a cryogenic probe. Structural variations in the pine and birch LCC preparations of different types (MWL, CEL and LCC-AcOH) were elucidated. The use of the high field NMR spectrometer equipped with the cryogenic probe resulted in a remarkable improvement in the resolution of the LCC signals and, therefore, is of primary importance for an accurate quantification of LCC linkages. The preparations investigated showed the presence of different amounts of benzyl ether, γ-ester and phenyl glycoside LCC bonds. Benzyl ester moieties were not detected. Pine LCC-AcOH and birch MWLc preparations were preferable for the analysis of phenyl glycoside and ester LCC linkages in pine and birch, correspondingly, whereas CEL preparations were the best to study benzyl ether LCC structures. The data obtained indicate that pinewood contains higher amounts of benzyl ether LCC linkages, but lower amounts of phenyl glycoside and γ-ester LCC moieties as compared to birch wood.}, number={6}, journal={PLANTA}, author={Balakshin, Mikhail and Capanema, Ewellyn and Gracz, Hanna and Chang, Hou-min and Jameel, Hasan}, year={2011}, month={Jun}, pages={1097–1110} }
 @article{koo_treasure_jameel_phillips_chang_park_2011, title={Reduction of enzyme dosage by oxygen delignification and mechanical refining for enzymatic hydrolysis of green liquor-pretreated hardwood}, volume={165}, DOI={10.1007/s12010-011-9301-4}, abstractNote={In this study, a strategy to reduce enzyme dosage is evaluated by applying two post-treatments, oxygen delignification and mechanical refining. The sugar conversion for GL12 substrates was increased from 51.5% to 77.9% with post-treatments at the enzyme dosage of 10 FPU. When the amount of enzyme was reduced to 5 FPU with post-treatments, the conversion of 71.8% was obtained, which was significant higher than the conversion without any post-treatment using 10 FPU (51.5%). This clearly demonstrates the benefit of post-treatments that allows more than 50% of enzyme reduction at the same level of enzymatic conversion. Enzyme-accessible surface area and pore volume were evaluated by Simons' staining and DSC thermoporometry methods, and strong correlations were found with the sugar conversion.}, number={3-4}, journal={Applied Biochemistry and Biotechnology}, author={Koo, B. W. and Treasure, T. H. and Jameel, H. and Phillips, R. B. and Chang, H. M. and Park, Sunkyu}, year={2011}, pages={832–844} }
 @article{yu_jameel_chang_park_2011, title={The effect of delignification of forest biomass on enzymatic hydrolysis}, volume={102}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2011.07.001}, abstractNote={The effect of delignification methods on enzymatic hydrolysis of forest biomass was investigated using softwood and hardwood that were pretreated at an alkaline condition followed by sodium chlorite or ozone delignification. Both delignifications improved enzymatic hydrolysis especially for softwood, while pretreatment alone was found effective for hardwood. High enzymatic conversion was achieved by sodium chlorite delignification when the lignin content was reduced to 15%, which is corresponding to 0.30–0.35 g/g accessible pore volume, and further delignification showed a marginal effect. Sample crystallinity index increased with lignin removal, but it did not show a correlation with the overall carbohydrate conversion of enzymatic hydrolysis.}, number={19}, journal={BIORESOURCE TECHNOLOGY}, author={Yu, Zhiying and Jameel, Hasan and Chang, Hou-min and Park, Sunkyu}, year={2011}, month={Oct}, pages={9083–9089} }
 @article{gonzalez_jameel_chang_treasure_pirraglia_saloni_2011, title={Thermo-mechanical pulping as a pretreatment for agricultural biomass for biochemical conversion}, volume={6}, number={2}, journal={BioResources}, author={Gonzalez, R. and Jameel, H. and Chang, H. M. and Treasure, T. and Pirraglia, A. and Saloni, D.}, year={2011}, pages={1599–1614} }
 @article{lee_jameel_venditti_2010, title={A comparison of the autohydrolysis and ammonia fiber explosion (AFEX) pretreatments on the subsequent enzymatic hydrolysis of coastal Bermuda grass}, volume={101}, ISSN={0960-8524}, url={http://dx.doi.org/10.1016/j.biortech.2010.02.055}, DOI={10.1016/j.biortech.2010.02.055}, abstractNote={Two distinct pretreatment technologies, autohydrolysis and AFEX, have been applied to coastal Bermuda grass (CBG) followed by enzymatic hydrolysis in order to compare the effects of pretreatment on the subsequent sugar generation. Furthermore, the influence of structural features from each pretreatment on biomass digestibility was characterized with SEM, ATR-FTIR, and XRD. Enzymatic conversion of pretreated solids from the pretreatments increased with elevated temperature and longer residence times. AFEX pretreatment at 100 °C for 30 min produced a sugar yield of 94.8% of theoretical possible with 30 FPU/g enzymatic loading, the maximum achieved with AFEX. It was also shown that with autohydrolysis at 170 °C for 60 min that 55.4% sugar yield of the theoretical possible was produced with a 30 FPU/g enzymatic loading, the maximum with autohydrolysis. AFEX pretreatment does not change the chemical composition of CBG but autohydrolysis reduces hemicellulose content in the pretreated solids. Both pretreatments cause re-localization of lignin components. There was no observed correlation between crystallinity and enzyme digestibility of the pretreated solids. AFEX pretreatment developed more enzymatic accessibility to pretreated solids of CBG than did autohydrolysis pretreatment, leading to more sugar generation through the whole process. The total amount of sugars accounted for with autohydrolysis decreases with increasing temperature, consistent with increased byproduct generation via thermal degradation reactions.}, number={14}, journal={Bioresource Technology}, publisher={Elsevier BV}, author={Lee, Jung Myoung and Jameel, Hasan and Venditti, Richard A.}, year={2010}, month={Jul}, pages={5449–5458} }
 @article{lee_jameel_venditti_2010, title={Effect of ozone and autohydrolysis pretreatments on enzymatic digestibility of coastal bermuda grass}, volume={5}, DOI={10.15376/biores.5.2.1084-1101}, abstractNote={Coastal Bermuda grass (CBG) has been shown to have potential as a biomass feedstock for sugar production. In this study, the effectiveness of ozone pretreatment for CBG to improve the sugar recovery via enzyme hydrolysis was investigated. Raw CBG and autohydrolysis-treated CBG were pretreated with ozone at ozone consumption of 1.8 to 26.4 % (w/w) at room temperature. Lignin degradation and hemicellulose solubilization increased with increased ozone consumption. At 26.4% ozone consumption by weight on CBG the amount of lignin in the CBG was reduced by 34%. Autohydrolysis of CBG increased the reactivity of cellulose, hemicellulose, and lignin with ozone. The maximum total sugar recovery after enzymatic hydrolysis was 32% for a 14.0% consumption of ozone on raw CBG. For CBG samples pretreated with autohydrolysis followed by a 3.1% ozone consumption pretreatment the maximum total sugar recovery after enzyme hydrolysis was 40.1%. Autohydrolysis pretreatment followed by enzyme hydrolysis yielded a 36.4% sugar recovery, indicating that the application and benefits of ozone after autohydrolysis with the conditions studied herein are marginally better than autohydrolysis alone.}, number={2}, journal={BioResources}, author={Lee, J. M. and Jameel, H. and Venditti, R. A.}, year={2010}, pages={1084–1101} }
 @article{jin_jameel_chang_phillips_2010, title={Green Liquor Pretreatment of Mixed Hardwood for Ethanol Production in a Repurposed Kraft Pulp Mill}, volume={30}, ISSN={["1532-2319"]}, DOI={10.1080/02773810903578360}, abstractNote={Abstract The development of a new, relatively simple process, which uses green liquor (sodium carbonate and sodium sulfide) as a pretreatment for the production of ethanol is described in this article. The pulps produced by this process can be enzymatically hydrolyzed to monomeric sugars with a high overall sugar recovery. The use of green liquor for pretreatment ensures that the chemicals used during pretreatment can be recovered efficiently using proven technology and can be easily implemented in a repurposed kraft pulp mill. The yield of pulps produced by the green liquor pretreatment process is about 80% with nearly 100% cellulose and 75% xylan in retention in mixed southern hardwood. The low pH prevents the random hydrolysis of polysaccharide and secondary peeling reactions from occurring during the pretreatment, resulting in higher retention of the polysaccharides in pulp. About 35% of the lignin is removed during the green liquor pretreatment process, which is sufficient for efficient enzymatic hydrolysis. The amount of sugar produced in enzymatic hydrolysis increased with both the green liquor and enzyme charge. The increase in enzymatic hydrolysis efficiency was small as the total titrateable alkali was increased beyond 12–16%. With green liquor pretreatment at 16% Total Titrateable Alkali (TTA), the overall sugar recovery for hardwood was shown to be around 77% at a cellulase charge of 20 FPU/gm of substrate. A sugar recovery of 80% could be achieved at higher enzyme charges. These levels of sugar recovery are competitive with other pretreatments for hardwood. This novel pretreatment process can be used to repurpose kraft mills, which are being closed due to a decrease in the demand for paper in North America, for production of ethanol.}, number={1}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Jin, Yongcan and Jameel, Hasan and Chang, Hou-min and Phillips, Richard}, year={2010}, pages={86–104} }
 @inproceedings{lucia_jameel_banerjee_venditti_phillips_diaz_2010, title={Green liquor as a novel pretreatment agent to derive higher value wood products}, booktitle={Research Progress in Paper Industry and Biorefinery (4th ISETPP), vols 1-3}, author={Lucia, L. A. and Jameel, H. and Banerjee, S. and Venditti, R. and Phillips, R. and Diaz, J.}, year={2010}, pages={708–711} }
 @article{wu_chang_jameel_philips_2010, title={Novel Green Liquor Pretreatment of Loblolly Pine Chips to Facilitate Enzymatic Hydrolysis into Fermentable Sugars for Ethanol Production}, volume={30}, ISSN={["1532-2319"]}, DOI={10.1080/02773811003746717}, abstractNote={Abstract Softwood species generally have been found very recalcitrant to enzymatic hydrolysis of the carbohydrate fractions to monomeric sugars. To solve this problem, loblolly pine chips were pretreated with green liquor at 12–20% Total Titratable Alkali (TTA) (as Na2O on wood) at 170°C for 800 H-factor. The yield of resulting pulp was 76.5–78.6% and the lignin content decreased from 29.2 to 20.2–22.4% and the total polysaccharide decreased from 62.6 to 53.8–55.0%, all based on the weight of original wood. When the pulp was subjected to enzymatic hydrolysis using 40 Filter Paper Unit (FPU)/g pulp, only 41% of the polysaccharides in wood were converted to monomeric sugars. This conversion figure is much lower than that of mixed southern hardwoods (80%) treated under similar conditions. If the green liquor treated pulp was further subjected to either oxygen delignification or mechanical refining prior to the enzymatic hydrolysis, the conversion rate increased to around 55% and 60%, respectively. Furthermore, combination of oxygen delignification and refining further increased the total sugar conversion to 78% of the total sugar in wood, approximately equal to that of the mixed southern hardwoods.}, number={3}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Wu, Shu-fang and Chang, Hou-min and Jameel, Hasan and Philips, Richard}, year={2010}, pages={205–218} }
 @article{lee_shi_venditti_jameel_2009, title={Autohydrolysis pretreatment of Coastal Bermuda grass for increased enzyme hydrolysis}, volume={100}, ISSN={["1873-2976"]}, DOI={10.1016/j.biortech.2008.12.068}, abstractNote={Coastal Bermuda grass (GBG) was pretreated using an autohydrolysis process with different temperatures and times, and the pretreated materials were enzymatically hydrolyzed using a mixture of cellulase, xylanase and β-glucosidase with different enzyme loadings to evaluate sugar yields. Compared with untreated CBG, autohydrolysis pretreatments at all elevated temperatures and residence times tested enhanced enzymatic digestibility of both cellulose and hemicellulose. Increasing the temperature and residence time also helps to solubilize hemicelluloses, with 83.3% of the hemicelluloses solubilized at 170 °C for 60 min treatment. However, higher temperatures and longer times resulted in an overall lower sugar recovery when considering monosaccharides in the prehydrolyzate combined with the enzyme hydrolyzate. Autohydrolysis at 150 °C for 60 min provided the highest overall sugar yield for the entire process. A total of 43.3 g of sugars, 70% of the theoretical sugar yield, can be generated from 100 g CBG, 15.0 g of monosaccharide in the prehydrolyzate and 28.3 g in the enzyme hydrolyzate. The conversion efficiency could be further improved by optimizing enzyme dosages and xylanases:cellulases ratio and pretreatment conditions to minimize sugar degradation.}, number={24}, journal={BIORESOURCE TECHNOLOGY}, author={Lee, Jung Myoung and Shi, Jian and Venditti, Richard A. and Jameel, Hasan}, year={2009}, month={Dec}, pages={6434–6441} }
 @article{chi_zhang_chang_jameel_2009, title={Determination of Furfural and Hydroxymethylfurfural Formed From Biomass Under Acidic Conditions}, volume={29}, ISSN={["0277-3813"]}, DOI={10.1080/02773810903096025}, abstractNote={Abstract A rapid method for simultaneous determination of furfural and hydroxymethylfurfural (HMF) in the filtrate of an acidic treatment of biomass was developed based on UV spectrophotometer. Interference from acid soluble lignin is alleviated by the use of absorbance difference spectrum before and after reduction with sodium borohydride (NaBH4). The concentrations of furfural and HMF in the filtrate are determined by measuring the absorbance of the difference spectrum at 277 nm and 285 nm, the characteristic absorption maxima for furfural and HMF, respectively. Two simultaneous equations are solved to obtain the concentrations of furfural and HMF in the filtrate. Acid soluble lignin in the solution is determined to cause negligible interference on the analysis.}, number={4}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Chi, Congcong and Zhang, Zeng and Chang, Hou-min and Jameel, Hasan}, year={2009}, pages={265–276} }
 @article{chi_zhang_ge_jameel_2009, title={The relationship between two methods for evaluating five-carbon sugars in eucalyptus extraction liquor}, volume={4}, number={2}, journal={BioResources}, author={Chi, C. C. and Zhang, Z. and Ge, W. W. and Jameel, H.}, year={2009}, pages={537–543} }
 @article{pu_ragauskas_lucia_naithani_jameel_2008, title={Near-infrared spectroscopy and chemometric analysis for determining oxygen delignification yield}, volume={28}, ISSN={["0277-3813"]}, DOI={10.1080/02773810802125008}, abstractNote={Abstract Oxygen delignification studies were carried out using a softwood kraft pulp under varying reaction temperatures (80–140°C) and alkaline charges (1–12%). Near-infrared (NIR) spectroscopy combined with chemometric methods was employed to analyze oxygen delignification pulp yields, which were compared to gravimetric analysis. Principal component analysis (PCA) of the NIR spectra data was performed and a partial least-square (PLS) regression model was developed to predict the pulp yield of oxygen delignified pulps based on the NIR spectra data. PCA analysis indicated that 99.1% of total variances of NIR spectra data in the range of 1100–2266 nm could be expressed by three principle components. A PLS1 model based on the NIR spectra data had good predictive ability and appeared to be an effective tool for pulp yield prediction for the oxygen delignification process.}, number={2}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Pu, Yunqiao and Ragauskas, Arthur J. and Lucia, Lucian A. and Naithani, Ved and Jameel, Hasan}, year={2008}, pages={122–136} }
 @article{kadla_jameel_2008, title={Professor Hou-Min Chang 2007 ISWFPC Notable Achievement Award}, volume={28}, ISSN={["0277-3813"]}, DOI={10.1080/02773810802124753}, number={2}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Kadla, John F. and Jameel, Hasan}, year={2008}, pages={67–68} }
 @article{park_venditti_jameel_pawlak_2007, title={Hard-to-remove water in cellulose fibers characterized by thermal analysis: A model for the drying of wood-based fibers}, volume={6}, number={7}, journal={TAPPI Journal}, author={Park, S. and Venditti, R. A. and Jameel, H. and Pawlak, J. J.}, year={2007}, pages={10–16} }
 @article{park_venditti_jameel_pawlak_2007, title={Studies of the heat of vaporization of water associated with cellulose fibers characterized by thermal analysis}, volume={14}, ISSN={["0969-0239"]}, DOI={10.1007/s10570-007-9108-1}, number={3}, journal={CELLULOSE}, author={Park, Sunkyu and Venditti, Richard A. and Jameel, Hasan and Pawlak, Joel J.}, year={2007}, month={Jun}, pages={195–204} }
 @article{park_venditti_abrecht_jameel_pawlak_lee_2007, title={Surface and pore structure modification of cellulose fibers through cellulase treatment}, volume={103}, ISSN={["0021-8995"]}, DOI={10.1002/app.25457}, abstractNote={Abstract}, number={6}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Park, Sunkyu and Venditti, Richard A. and Abrecht, David G. and Jameel, Hasan and Pawlak, Joel J. and Lee, Jung M.}, year={2007}, month={Mar}, pages={3833–3839} }
 @article{lindstrom_naithani_kirkman_jameel_2006, title={A low-temperature, black liquor gasifier model for use in WinGEMS}, volume={5}, number={2}, journal={TAPPI Journal}, author={Lindstrom, M. and Naithani, V. and Kirkman, A. and Jameel, H.}, year={2006}, pages={20–24} }
 @article{park_venditti_jameel_pawlak_2006, title={A novel method to evaluate fibre hornification by high resolution thermogravimetric analysis}, volume={59}, number={6}, journal={Appita Journal}, author={Park, S. and Venditti, R. A. and Jameel, H. and Pawlak, J. J.}, year={2006}, pages={481–485} }
 @article{park_venditti_jameel_pawlak_2006, title={Changes in pore size distribution during the drying of cellulose fibers as measured by differential scanning calorimetry}, volume={66}, ISSN={0144-8617}, url={http://dx.doi.org/10.1016/j.carbpol.2006.02.026}, DOI={10.1016/j.carbpol.2006.02.026}, abstractNote={Changes in pore size distribution during the drying of cellulose fibers were determined using differential scanning calorimetry (DSC) with an isothermal step melting procedure. Softwood bleached kraft pulp at various moisture ratios were generated from partial drying in a thermogravimetric analyzer and then analyzed in a DSC. The pore size distribution was calculated using the Gibbs–Thomson equation and specific melting point depression of water detected by DSC. It was observed that larger pores collapse first followed by the sequential collapse of smaller pores. It is suggested that pore wall collapse resistance is the primary factor that determines which size pores close. The average measured pore size in the fiber wall of the never dried fiber was calculated to be about 80 nm and reduced with drying of the fibers. A constant pore size of about 20 nm was observed at moisture ratios below 0.3 g/g, which corresponds to one-to-two layers of non-freezing bound water tightly bound to the surface.}, number={1}, journal={Carbohydrate Polymers}, publisher={Elsevier BV}, author={Park, S and Venditti, R and Jameel, H and Pawlak, J}, year={2006}, month={Oct}, pages={97–103} }
 @article{zhang_pu_chai_naithani_jameel_ragauskas_2006, title={Elucidating carboxylic acid profiles for extended oxygen delignification of high-kappa softwood kraft pulps}, volume={60}, ISSN={["1437-434X"]}, DOI={10.1515/HF.2006.020}, abstractNote={Abstract}, number={2}, journal={HOLZFORSCHUNG}, author={Zhang, DC and Pu, YQ and Chai, XS and Naithani, V and Jameel, H and Ragauskas, AJ}, year={2006}, month={Mar}, pages={123–129} }
 @article{park_venditti_jameel_pawlak_2006, title={Hard to remove water in cellulose fibers characterized by high resolution thermogravimetric analysis - methods development}, volume={13}, ISSN={0969-0239 1572-882X}, url={http://dx.doi.org/10.1007/s10570-005-9009-0}, DOI={10.1007/s10570-005-9009-0}, number={1}, journal={Cellulose}, publisher={Springer Science and Business Media LLC}, author={Park, Sunkyu and Venditti, Richard A. and Jameel, Hasan and Pawlak, Joel J.}, year={2006}, month={Nov}, pages={23–30} }
 @article{svenson_jameel_chang_kadla_2006, title={Inorganic reactions in chlorine dioxide bleaching of softwood kraft pulp}, volume={26}, ISSN={["0277-3813"]}, DOI={10.1080/02773810601023255}, abstractNote={Abstract A softwood kraft pulp (27 kappa) was bleached with chlorine dioxide to various end pH values. The formation of chlorite, chlorate, and chloride was measured to quantify the amount of chlorine dioxide wasted as a function of pH during a Do (pre‐bleaching) stage. Chlorate formation increased with a decrease in final pH. Conversely, residual chlorite increased with an increase in the final pH. After 120 min of bleaching the total residual chlorite and chlorate showed that no substantial increase in residual oxidant occurs when bleaching to an end pH below 3.4. As a result, the brightness and permanganate numbers for low pH chlorine dioxide bleached pulps did not differ when bleaching to an end pH between 3.4 and 1.8. However, decreasing the pH below 3.4 did result in increased organic chloride formation. The results are contrary to previous studies where the maximum bleaching efficiency for a D1 stage was reported to occur when the end pH was between 3 and 4.}, number={3}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Svenson, Douglas R. and Jameel, Hasan and Chang, Hou-min and Kadla, John F.}, year={2006}, pages={201–213} }
 @article{dai_jameel_chang_2006, title={Precipitation of extractives onto kraft pulps during black liquor recycling in extended delignification process}, volume={26}, ISSN={["0277-3813"]}, DOI={10.1080/02773810600582210}, abstractNote={Abstract Our objective was to study the extractives content and the bleachability of batch extended delignified kraft pulps during the black liquor recycling. Extractives accumulated in the black liquor during the black liquor recycling. Some of the extractives in the black liquor precipitated on the pulps in the pretreatment stage, which affected the bleachability of pulps. For softwood, after 5 stages of black liquor recycling, the extractive content of the kraft pulps increased by up to 4 times and the final brightness decreased up to 2.4% ISO. The amount of extractives precipitating on the pulps strongly depended on the final pH of the pretreatment black liquor, which was determined by the operating conditions such as sulfidity, alkali charge, and pretreatment temperature. High alkalinity and low pretreatment temperature was the most efficient combination to minimize extractives from precipitating, and to maintain high bleachability of the kraft pulps. For hardwood, large amounts of extractives precipitated onto fibers, and the extractive content, especially the neutral extractive content, of the hardwood kraft pulps was high. During the black liquor recycling, the drop of the final brightness of hardwood kraft pulps was larger than that of the softwood kraft pulps.}, number={1}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Dai, QZ and Jameel, H and Chang, HM}, year={2006}, pages={35–51} }
 @article{holtman_chang_jameel_kadla_2006, title={Quantitative C-13 NMR characterization of milled wood lignins isolated by different milling techniques}, volume={26}, ISSN={["1532-2319"]}, DOI={10.1080/02773810600582152}, abstractNote={Abstract Milled wood lignins (MWL) prepared from finely milled wood flour produced by different milling techniques were compared by quantitative 13C NMR. Wood meal produced in a Wiley mill was milled for either six weeks in a porcelain rotary mill with porcelain balls, or by two variations of our standard technique. Specifically the Wiley wood meal was milled for one week in the rotary mill followed by 48 h of vibratory ball‐milling with steel balls either in toluene or under a N2 atmosphere. Results showed that the vibratory‐milled samples were similar in structure with the exception that the preparation milled under N2 had higher aliphatic and phenolic hydroxyl contents. The rotary‐milled sample on the other hand had a much lower β‐O‐4′ and hydroxyl content along with a higher degree of condensation and oxidized side chain structures.}, number={1}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Holtman, KM and Chang, HM and Jameel, H and Kadla, JF}, year={2006}, pages={21–34} }
 @inproceedings{park_venditti_pawlak_jameel_2005, title={High resolution thermo-gravimetric analysis of pulp drying}, booktitle={Advances in Paper Science and Technology: Transactions of the 13th Fundamental research symposium, vols 1-3}, author={Park, S. and Venditti, R. A. and Pawlak, J. J. and Jameel, H.}, year={2005}, pages={161–186} }
 @article{park_venditti_jameel_pawlak_2005, title={The  effect of fibre properties on fibre fractionation using a hydrocyclone}, volume={31}, number={3}, journal={Journal of Pulp and Paper Science}, author={Park, S. and Venditti, R. A. and Jameel, H. and Pawlak, J. J.}, year={2005}, pages={132–137} }
 @article{svenson_chang_jameel_kadla_2005, title={The role of non-phenolic lignin in chlorate-forming reactions during chlorine dioxide bleaching of softwood kraft pulp}, volume={59}, ISSN={["1437-434X"]}, DOI={10.1515/HF.2005.017}, abstractNote={Abstract}, number={2}, journal={HOLZFORSCHUNG}, author={Svenson, DR and Chang, HM and Jameel, H and Kadla, JF}, year={2005}, pages={110–115} }
 @article{dai_jameel_chang_kadla_2004, title={Bleachability of kraft pulps from earlywood and latewood of fast-growing loblolly pine}, volume={24}, ISSN={["0277-3813"]}, DOI={10.1081/wct-200046256}, abstractNote={Abstract The pulping and bleaching properties of earlywood and latewood of a fast‐growing loblolly pine were studied. Under the same pulping condition, the kappa number of the latewood kraft pulp was higher than that of the earlywood. At around the same kappa number, the yield of the latewood was higher than that of the earlywood. The bleaching results showed that the latewood kraft pulp had lower bleachability than the earlywood kraft pulp, due to its thicker cell wall and slower leaching rate.}, number={4}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Dai, QZ and Jameel, H and Chang, HM and Kadla, JF}, year={2004}, pages={357–370} }
 @article{lemeune_jameel_chang_kadla_2004, title={Effects of ozone and chlorine dioxide on the chemical properties of cellulose fibers}, volume={93}, ISSN={["1097-4628"]}, DOI={10.1002/app.20509}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Lemeune, S and Jameel, H and Chang, HM and Kadla, JF}, year={2004}, month={Aug}, pages={1219–1223} }
 @inproceedings{yu_capanema_batista_josserand_johnson_nelson_mckeand_mackay_kadla_li_et al._2004, title={Tracking down the effects of a rare mutant gene in loblolly pine: a first report}, booktitle={2004 Paper Summit, Spring Technical and International Environmental Conference}, publisher={CD-ROM published by TAPPI,  Norcross, GA}, author={Yu, Q. and Capanema, E. and Batista, V. B. and Josserand, S. and Johnson, G. and Nelson, C. D. and McKeand, S. E. and MacKay, J. J. and Kadla, J. F. and Li, B. and et al.}, year={2004} }
 @article{holtman_chang_jameel_kadla_2003, title={Elucidation of lignin structure through degradative methods: Comparison of modified DFRC and thioacidolysis}, volume={51}, ISSN={["0021-8561"]}, DOI={10.1021/jf0340411}, abstractNote={Milled wood and milled wood lignin (MWL) samples were subjected to DFRC and thioacidolysis. Despite the fact that both methods selectively cleave aryl ether bonds, substantial differences in results were obtained. Lignin thioacidolysis gave total molar yields of degradation monomer products in the range of 3.5-7 mol % higher than DFRC. GPC analysis showed that the thioacidolysis-treated lignin was degraded to a lower average molecular weight than that treated by DFRC. Contrary to results reported for lignin model compounds, these results indicate that the DFRC method does not completely or efficiently degrade the lignin polymer. In fact, the DFRC-degraded lignin retained much of the characteristics of the original MWL. Elemental analysis revealed the presence of bromine in the DFRC-treated lignin, and two-dimensional (1)H-(13)C HMQC NMR spectroscopy showed the presence of beta-O-4 linkages in the DFRC-treated lignin. No beta-O-4 interunit linkages were detected in the thioacidolysis-treated lignin. These results are consistent with the lower monomer yields and the higher average molecular weight of the DFRC-treated lignin and indicate inefficiency in the chemistry of the method, probably due to steric constraints of the polymeric nature of lignin.}, number={12}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Holtman, KM and Chang, HM and Jameel, H and Kadla, JF}, year={2003}, month={Jun}, pages={3535–3540} }
 @article{yang_lucia_ragauskas_jameel_2003, title={Oxygen delignification chemistry and its impact on pulp fibers}, volume={23}, ISSN={["1532-2319"]}, DOI={10.1081/WCT-120018613}, abstractNote={Abstract Two southern pine kraft pulps with kappa numbers of 30.0 (SW1-0) and 48.0 (SW2-0) were oxygen delignified by 30–60% by varying the reaction temperature (78–110°C) and charge of sodium hydroxide (1.6–4.4%). O-bleachability was found to be correlated to the incoming kappa number and charge of sodium hydroxide employed. In general, a lower charge of caustic and a higher brownstock kappa number improved pulp bleachability. The residual lignin in the brownstocks and O-delignified kraft pulp samples was isolated and characterized by 13C and 31P NMR. 13C NMR analysis of the residual lignin samples indicated that the post-oxygen delignified pulps were enriched with α-carbonyl groups and carboxylic acid groups. The content of β-O-aryl structures was increased by 23–36% depending on the extent of oxygen delignification. The post-oxygen delignified pulps were also shown to have increased substituted aryl carbons. 31P NMR indicated that the relative content of condensed phenolic units increased by 9–20% after the oxygen delignification, depending on the severity of the O-stage. This observation was probably due to the accumulation or formation of 5,5-biphenyl structures in the process. The physical strength properties of brownstock and post-oxygen delignified pulps were assessed in terms of zero-span strength, tensile strength, tear strength, and burst strength. Oxygen delignification led to a slight increase in the curls and kinks of the pulp fibers. The O-stage was shown to cause a 4.8–15.6% decrease in zero-span strength. In contrast, oxygen delignification increased tensile strength. This result could be explained as the improvement of fiber bonding after the oxygen bleaching.}, number={1}, journal={JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY}, author={Yang, RM and Lucia, L and Ragauskas, AJ and Jameel, H}, year={2003}, pages={13–29} }
 @article{zhu_kadla_chang_jameel_2003, title={Reactions of lignin with peroxymonophosphoric acid: The degradation of lignin model compounds}, volume={57}, ISSN={["0018-3830"]}, DOI={10.1515/HF.2003.007}, abstractNote={Summary}, number={1}, journal={HOLZFORSCHUNG}, author={Zhu, T and Kadla, JF and Chang, HM and Jameel, H}, year={2003}, pages={44–51} }
 @article{kishimoto_kadla_chang_jameel_2003, title={The reactions of lignin model compounds with hydrogen peroxide at low pH}, volume={57}, ISSN={["1437-434X"]}, DOI={10.1515/HF.2003.008}, abstractNote={Summary}, number={1}, journal={HOLZFORSCHUNG}, author={Kishimoto, T and Kadla, JF and Chang, HM and Jameel, H}, year={2003}, pages={52–58} }
 @article{svenson_kadla_chang_jameel_2002, title={Effect of pH on the inorganic species involved in a chlorine dioxide reaction system}, volume={41}, DOI={10.1021/ie020191}, number={24}, journal={Industrial & Engineering Chemistry Research}, author={Svenson, D. R. and Kadla, J. F. and Chang, H. M. and Jameel, H.}, year={2002}, pages={5927–5933} }
 @article{svenson_kadla_chang_jameel_2002, title={Effect of pH on the mechanism of OClO center dot oxidation of aromatic compounds}, volume={80}, ISSN={["0008-4042"]}, DOI={10.1139/V02-089}, abstractNote={ Contrary to previous reports, the reaction mechanism of chlorine dioxide (OClO·) with benzyl alcohols involves both radical cation and benzyl radical mechanisms dependent on pH. The primary reaction product between OClO· and 1-(3,4-dimethoxy-phenyl) ethanol at pH 8 is 3,4-dimethoxyacetophenone. At pH 4 no acetophenone was observed; the majority of the degradation products were chlorinated and aromatic ring-oxidized compounds. A primary kinetic isotope effect (kH/kD = 2.05) was observed in the reaction of OClO· with 1-(3,4-dimethoxy-phenyl)-(1-2H) ethanol at pH 8, but was absent at pH 4 (kH/kD [Formula: see text] 1). Similarly, the corresponding methyl ether (4-(1-methoxy)ethyl-1,2-dimethoxybenzene) was substantially less reactive at pH > 6. On the basis of these results, competing pH-dependent reaction mechanisms have been proposed, where at high pH OClO· reacts with benzyl alcohols via a OClO·–benzyl alcohol complex.Key words: chlorine dioxide, mechanism, kinetic isotope effect, aromatic radical cation, benzyl radical. }, number={7}, journal={CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE}, author={Svenson, D and Kadla, JF and Chang, HM and Jameel, H}, year={2002}, month={Jul}, pages={761–766} }
 @article{yang_lucia_ragauskas_jameel_2002, title={Oxygen Degradation and Spectroscopic Characterization of Hardwood Kraft Lignin}, volume={41}, ISSN={0888-5885 1520-5045}, url={http://dx.doi.org/10.1021/ie020007k}, DOI={10.1021/ie020007k}, abstractNote={A series of sweet gum kraft pulps with initial kappa numbers ranging from 29 to 13.6 was subjected to oxygen delignification employing 1.00 and 4.00% charges of caustic. The O-delignified pulps were characterized according to lignin content, pulp yield, and viscosity. In addition, residual lignin samples were isolated from the kraft brownstock and the post-oxygen-delignified kraft pulps, along with the corresponding O-effluents. The structural changes of these lignins during oxygen delignification were investigated using UV spectroscopy and advanced NMR techniques. Differential UV spectra indicated that lignins isolated from oxygen-delignified kraft pulp and its effluent were significantly reduced at λmax 260, 280, and 370 nm in comparison to the brownstock lignins. These changes in absorbance are attributed to the degradation of phenolic and stilbene structures during oxygen delignification. 31P NMR lignin data revealed that the primary sites of oxidation during an O-stage were syringyl and guaiacyl phen...}, number={24}, journal={Industrial & Engineering Chemistry Research}, publisher={American Chemical Society (ACS)}, author={Yang, R. and Lucia, L. and Ragauskas, A. and Jameel, H.}, year={2002}, month={Oct}, pages={5941–5948} }
 @article{ikeda_holtman_kadla_chang_jameel_2002, title={Studies on the effect of ball milling on lignin structure using a modified DFRC method}, volume={50}, ISSN={["0021-8561"]}, DOI={10.1021/jf010870f}, abstractNote={The structures of milled wood lignin (MWL), cellulolytic enzyme lignin (CEL), and residual lignin (REL) from a loblolly pine were analyzed using a modified derivatization followed by reductive cleavage (DFRC) method developed to allow the quantitative determination of three different structural monomeric products originating in lignin: phenolic beta-O-4, alpha-O-4, and etherified beta-O-4 structures. Results show that MWL and CEL are structurally identical, with an increased phenolic beta-O-4 content compared to that of the original Wiley milled wood. These results indicate that the portion of lignin linked to carbohydrates and that not linked to carbohydrates are structurally the same. Modified DFRC analysis of the effect of ball milling on the structure of lignin in wood, MWL, CEL, and REL indicate that vibratory ball milling does not change the lignin structure provided certain precautions are taken. Specifically, dry vibratory ball milling under a nitrogen atmosphere causes substantial structural changes including condensation, whereas vibratory ball milling in toluene had little effect on the lignin structure. This indicates that the structural differences observed in MWL and CEL arise because of the extraction procedure, which preferentially extracts phenolic lignin structures. MWL and CEL are representative of the total lignin in wood; however, due primarily to the solvent extraction process, higher phenolic hydroxyl contents are observed. Nitrobenzene oxidation showed structural results similar to those from the modified DFRC method.}, number={1}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Ikeda, T and Holtman, K and Kadla, JF and Chang, HM and Jameel, H}, year={2002}, month={Jan}, pages={129–135} }
 @article{lucas_venditti_jameel_2001, title={Behavior of pressure sensitive adhesive material in industrial pressure screens and laboratory screens.}, volume={84}, number={5}, journal={TAPPI Journal}, author={Lucas, B. E. and Venditti, R. A. and Jameel, H.}, year={2001}, pages={70} }
 @inproceedings{jameel_robison_chang_mcmurray_2001, title={Pulping of short rotation sycamore coppice to maximize productivity}, number={CD-ROM}, booktitle={Proceedings of the TAPPI Pulping Conference}, publisher={Seattle, WA: TAPPI Press}, author={Jameel, H. and Robison, D. and Chang, H. and McMurray, J.}, year={2001} }
 @article{mackay_presnell_jameel_taneda_d o'malley_sederoff_1999, title={Modified lignin and delignification with a CAD-deficient loblolly pine}, volume={53}, ISSN={["0018-3830"]}, DOI={10.1515/HF.1999.067}, abstractNote={Summary}, number={4}, journal={HOLZFORSCHUNG}, author={MacKay, J and Presnell, T and Jameel, H and Taneda, H and D O'Malley and Sederoff, R}, year={1999}, pages={403–410} }
 @article{venditti_chang_jameel_1999, title={Overview of stickies research at North Carolina State University}, number={1999 Nov.}, journal={Paper Age}, author={Venditti, R. A. and Chang, H. M. and Jameel, H.}, year={1999}, pages={18–20} }
 @article{kadla_chang_jameel_1999, title={The reactions of lignins with high temperature hydrogen peroxide - Part 2. The oxidation of kraft lignin}, volume={53}, ISSN={["0018-3830"]}, DOI={10.1515/HF.1999.047}, abstractNote={Summary}, number={3}, journal={HOLZFORSCHUNG}, author={Kadla, JF and Chang, HM and Jameel, H}, year={1999}, pages={277–284} }
 @article{nemeth_jameel_joyce_kovacs_erdelyi_1998, title={Enzyme bleaching following Kraft/Anthraquinone or Kraft/Anthraquinone/Polysulfide pulping}, volume={32}, number={3-4}, journal={Cellulose Chemistry and Technology}, author={Nemeth, A. and Jameel, H. and Joyce, T. W. and Kovacs, I. and Erdelyi, D. J.}, year={1998}, pages={291–298} }
 @misc{chang_jameel_song_pan_amini_webster_evans_1997, title={Method of oxidatively treating a substrate with an equilibrium mixture of caro's acid and a percarboxylic acid}, volume={5,693,185}, number={1997 Dec. 2}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Chang, H.-M. and Jameel, H. and Song, J.-F. and Pan, D.-R. and Amini, B. and Webster, J. R. and Evans, B. A.}, year={1997} }
 @article{kadla_chang_jameel_1997, title={The reactions of lignins with hydrogen peroxide at high temperature .1. The oxidation of lignin model compounds}, volume={51}, ISSN={["0018-3830"]}, DOI={10.1515/hfsg.1997.51.5.428}, abstractNote={This work deals with hydrogen peroxide bleaching at high temperature (90°) using simple phenolic and non-phenolic model compounds of the benzyl alcohol and benzaldehyde types. In addition to the reactions of the phenolic representatives, proceeding via the well known Dakin and Dakin-like mechanisms, the non-phenolic compounds are shown to react at these higher temperatures via an S N 2 mechanism to give ultimately the corresponding benzoic acids and a dimeric ether compound.}, number={5}, journal={HOLZFORSCHUNG}, author={Kadla, JF and Chang, HM and Jameel, H}, year={1997}, pages={428–434} }
 @misc{chang_jameel_song_pan_amini_webster_evans_1996, title={Process for preparing a bleaching liquor containing percarboxylic acid and caro's acid}, volume={5,589,032}, number={1996 Dec. 31}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Chang, H. M. and Jameel, H. and Song, J. and Pan, D. and Amini, B. and Webster, J. R. and Evans, B. A.}, year={1996} }
 @misc{chang_jameel_seger_1993, title={High efficiency two-step, high-low pH chlorine dioxide pulp bleaching process}, volume={5,268,075}, number={1993 Dec. 7}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Chang, H. M. and Jameel, H. and Seger, G. E.}, year={1993} }