@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.}, 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{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 followed by delignifying with oxygen/NaOH, chlorine dioxide, or ozone to lower lignin levels. These pulps were subject to enzymatic saccharification to investigate the effects of lignin content and delignification methods. Kappa number is not a good indication of lignin content of chlorine dioxide- and oxygen-delignified pulps. Both the lignin content of the pulp and the method of delignification affect enzymatic saccharification. Decreasing lignin content of a given pulp improves saccharification efficiency. The delignification methods have a profound influence on enzymatic hydrolysis efficiency, with chlorine dioxide- and oxygen-delignified pulps being more efficient than ozone-delignified and kraft pulps. X-ray photoelectric spectroscopy analysis shows that the surface lignin content of the pulp may account for the difference between the three methods of oxidative delignification.}, 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{geng_venditti_pawlak_de assis_gonzalez_phillips_chang_2020, title={Techno-economic analysis of hemicellulose extraction from different types of lignocellulosic feedstocks and strategies for cost optimization}, volume={14}, ISBN={1932-1031}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/bbb.2054}, DOI={10.1002/bbb.2054}, number={2}, journal={BIOFUELS BIOPRODUCTS & BIOREFINING-BIOFPR}, publisher={Wiley}, author={Geng, Wenhui and Venditti, Richard A. and Pawlak, Joel J. and De Assis, Tiago and Gonzalez, Ronalds W. and Phillips, Richard B. and Chang, Hou-min}, year={2020}, month={Mar}, pages={225–241} } @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{de assis_iglesias_bilodeau_johnson_phillips_peresin_bilek_rojas_venditti_gonzalez_2018, title={Cellulose micro- and nanofibrils (CMNF) manufacturing - financial and risk assessment}, volume={12}, ISSN={1932-104X}, url={http://dx.doi.org/10.1002/bbb.1835}, DOI={10.1002/bbb.1835}, abstractNote={Abstract Conversion economics, risk, and financial analyses for an industrial facility manufacturing cellulose micro‐ and nanofibrils (CMNF) from wood pulp is presented. Process data is based on mass and energy balances from a pilot facility in the University of Maine. Here, CMNF is produced from untreated wood pulp by using disk refining, with an assumed production capacity of 50 t (dry metric ton equivalent) per day. Stand‐alone and co‐location manufacturing facilities were simulated and assessed. Minimum product selling prices (MPSP, estimated to achieve a 16% hurdle rate) for different scenarios ranged from USD 1893/t CMNF to USD 2440/t CMNF (dry equivalent). Pulp and energy consumption were identified as major cost drivers. Consequently, it was found that the use of alternative feedstock, in addition to co‐location configuration, can reduce MPSP by 37%. Since estimated MPSP of CMNF is lower than cellulose nanocrystals (CNC) – both estimated to achieve a 16% hurdle rate, we believe market adoption of CMNF in the near term is more promising, regardless of specific applications. This study provides state of the art business intelligence information on the conversion economics, risk, and financial analyses for CMNF manufacturing. Thus, the data represents valuable information to entrepreneurs, R&D scientists, and product developers who plan to adopt CMNF in their processes and products. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd}, number={2}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={de Assis, Camilla Abbati and Iglesias, Maria Celeste and Bilodeau, Michael and Johnson, Donna and Phillips, Richard and Peresin, Maria Soledad and Bilek, E.M. Ted and Rojas, Orlando J. and Venditti, Richard and Gonzalez, Ronalds}, year={2018}, month={Mar}, pages={251–264} } @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}, 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{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={Abstract 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{lopez_abt_dvorak_hodge_phillips_2018, title={Tree breeding model to assess financial performance of pine hybrids and pure species: deterministic and stochastic approaches for South Africa}, volume={49}, ISSN={["1573-5095"]}, DOI={10.1007/s11056-017-9609-1}, number={1}, journal={NEW FORESTS}, author={Lopez, Juan L. and Abt, Robert C. and Dvorak, William S. and Hodge, Gary R. and Phillips, Richard}, year={2018}, month={Jan}, pages={123–142} } @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{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}, 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{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{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={Abstract 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} } @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{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{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} } @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{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={Abstract 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} } @inproceedings{phillips_2012, title={Where and how will paper be made in the future?}, booktitle={Proceeding of the 4th International Conference on Pulping, Papermaking and Biotechnology (ICPPB '12), vols. I and II}, author={Phillips, R. B.}, year={2012}, pages={3–10} } @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{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{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} } @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{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}, 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{cubbage_koesbandana_mac donagh_rubilar_balmelli_morales olmos_de la torre_murara_hoeflich_kotze_et al._2010, title={Global timber investments, wood costs, regulation, and risk}, volume={34}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2010.05.008}, DOI={10.1016/j.biombioe.2010.05.008}, abstractNote={We estimated financial returns and wood production costs in 2008 for the primary timber plantation species. Excluding land costs, returns for exotic plantations in almost all of South America – Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay – were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each country, with most having Internal Rates of Return (IRRs) of 20% per year or more, as did teak. Pinus species in South America were generally closer to 15%, except in Argentina, where they were 20%. IRRs were less, but still attractive for plantations of coniferous or deciduous species in China, South Africa, New Zealand, Indonesia, and the United States, ranging from 7% to 12%. Costs of wood production at the cost of capital of 8% per year were generally cheapest for countries with high rates of return and for pulpwood fiber production, which would favor vertically integrated firms in Latin America. But wood costs at stumpage market prices were much greater, making net wood costs for open market wood more similar among countries. In the Americas, Chile and Brazil had the most regulatory components of sustainable forest management, followed by Misiones, Argentina and Oregon in the U.S. New Zealand, the United States, and Chile had the best rankings regarding risk from political, commercial, war, or government actions and for the ease of doing business. Conversely, Venezuela, Indonesia, Colombia, and Argentina had high risk ratings, and Brazil, Indonesia, and Venezuela were ranked as more difficult countries for ease of business.}, number={12}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Cubbage, Frederick and Koesbandana, Sadharga and Mac Donagh, Patricio and Rubilar, Rafael and Balmelli, Gustavo and Morales Olmos, Virginia and De La Torre, Rafael and Murara, Mauro and Hoeflich, Vitor Afonso and Kotze, Heynz and et al.}, year={2010}, month={Dec}, pages={1667–1678} } @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} }