@article{kim_lee_treasure_skotty_floyd_kelley_park_2019, title={Alkaline extraction and characterization of residual hemicellulose in dissolving pulp}, volume={26}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-018-2137-0}, number={2}, journal={CELLULOSE}, author={Kim, Chae Hoon and Lee, Joo and Treasure, Trevor and Skotty, Jennifer and Floyd, Thomas and Kelley, Stephen S. and Park, Sunkyu}, year={2019}, month={Jan}, pages={1323–1333} }
 @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{daystar_treasure_reeb_venditti_gonzalez_kelley_2015, title={Environmental impacts of bioethanol using the NREL biochemical conversion route: multivariate analysis and single score results}, volume={9}, ISSN={1932-104X}, url={http://dx.doi.org/10.1002/bbb.1553}, DOI={10.1002/bbb.1553}, abstractNote={AbstractMandated Environmental Protection Agency biofuel qualifications focused on greenhouse gas (GHG) emissions and fossil fuel use are limited in perspective and have the potential to encourage burden shifting. When a broader host of environmental impacts are examined, environmental trade‐offs often exist when biofuels are compared to gasoline. Multivariate analysis methods examining a wide variety of weighting value systems and methodology assumptions were used to determine process design options with the lowest overall environmental impact. A multivariate environmental analysis was applied to the dilute acid pre‐treatment process followed by enzymatic hydrolysis and the fermentation process for converting loblolly pine, eucalyptus, natural hardwood, switchgrass, and sweet sorghum biomass to ethanol. The influence of co‐product treatment method choices, inclusion of direct land‐use change, and electrical grid assumptions were examined using 16 different weighting methods to create a single score result. Biofuel system rankings based on GHG emissions following the Renewable Fuel Standards 2 (RFS2) methods were very sensitive to the co‐product treatment method, inclusion of land‐use change emissions, and energy grid assumptions. The multivariate analysis ranking was heavily influenced by other environmental impacts resulting from the production of process chemicals used in ethanol conversion. Weighting methods examined had no influence on the environmental preference ranking of the biofuel scenarios. Additionally, the biofuel ranking based on the RFS2 methodology was different than the ranking following the multivariate approach examining additional impacts. These findings demonstrate a robust approach to biofuel life cycle assessment (LCA) scenario analysis and suggest that the limited scope of the RFS2 environmental analysis could result in burden shifting. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd}, number={5}, journal={Biofuels, Bioproducts and Biorefining}, publisher={Wiley}, author={Daystar, Jesse and Treasure, Trevor and Reeb, Carter and Venditti, Richard and Gonzalez, Ronalds and Kelley, Steve}, year={2015}, month={May}, pages={484–500} }
 @article{daystar_treasure_gonzalez_reeb_venditti_kelley_2015, title={The NREL biochemical and thermochemical ethanol conversion processes: Financial and environmental analysis comparison}, volume={10}, DOI={10.15376/biores.10.3.5096-5116}, abstractNote={The financial and environmental performance of the National Renewable Energy Lab’s (NREL) thermochemical and biochemical biofuel conversion processes are examined herein with pine, eucalyptus, unmanaged hardwood, switchgrass, and sweet sorghum. The environmental impacts of the process scenarios were determined by quantifying greenhouse gas (GHG) emissions and TRACI impacts. Integrated financial and environmental performance metrics were introduced and used to examine the biofuel production scenarios. The thermochemical and biochemical conversion processes produced the highest financial performance and lowest environmental impacts when paired with pine and sweet sorghum, respectively. The high ash content of switchgrass and high lignin content of loblolly pine lowered conversion yields, resulting in the highest environmental impacts and lowest financial performance for the thermochemical and biochemical conversion processes, respectively. Biofuel produced using the thermochemical conversion process resulted in lower TRACI single score impacts and somewhat lower GHG emissions per megajoule (MJ) of fuel than using the biochemical conversion pathway. The cost of carbon mitigation resulting from biofuel production and corresponding government subsidies was determined to be higher than the expected market carbon price. In some scenarios, the cost of carbon mitigation was several times higher than the market carbon price, indicating that there may be other more cost-effective methods of reducing carbon emissions.}, number={3}, journal={BioResources}, author={Daystar, J. and Treasure, T. and Gonzalez, R. and Reeb, C. and Venditti, R. and Kelley, Stephen}, year={2015}, pages={5096–5116} }
 @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={AbstractThe 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{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={AbstractDilute 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{daystar_gonzalez_reeb_venditti_treasure_abt_kelley_2014, title={Economics, environmental impacts, and supply chain analysis of cellulosic biomass for biofuels in the Southern US: pine, eucalyptus, unmanaged hardwoods, forest residues, switchgrass, and sweet sorghum}, volume={9}, DOI={10.15376/biores.9.1.393-444}, abstractNote={The production of six regionally important cellulosic biomass feedstocks, including pine, eucalyptus, unmanaged hardwoods, forest residues, switchgrass, and sweet sorghum, was analyzed using consistent life cycle methodologies and system boundaries to identify feedstocks with the lowest cost and environmental impacts. Supply chain analysis was performed for each feedstock, calculating costs and supply requirements for the production of 453,592 dry tonnes of biomass per year. Cradle-to-gate environmental impacts from these modeled supply systems were quantified for nine mid-point indicators using SimaPro 7.2 LCA software. Conversion of grassland to managed forest for bioenergy resulted in large reductions in GHG emissions due to carbon uptake associated with direct land use change. By contrast, converting forests to cropland resulted in large increases in GHG emissions. Production of forest-based feedstocks for biofuels resulted in lower delivered cost, lower greenhouse gas (GHG) emissions, and lower overall environmental impacts than the agricultural feedstocks studied. Forest residues had the lowest environmental impact and delivered cost per dry tonne. Using forest-based biomass feedstocks instead of agricultural feedstocks would result in lower cradle-to-gate environmental impacts and delivered biomass costs for biofuel production in the southern U.S.}, number={1}, journal={BioResources}, author={Daystar, J. and Gonzalez, R. and Reeb, C. and Venditti, R. and Treasure, T. and Abt, R. and Kelley, Stephen}, year={2014}, pages={393–444} }
 @article{horhammer_treasure_gonzalez_heiningen_2014, title={Larch Biorefinery: Technical and Economic Evaluation}, volume={53}, ISSN={["0888-5885"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84893003854&partnerID=MN8TOARS}, DOI={10.1021/ie403653j}, abstractNote={In this study a forest biorefinery concept based on larch wood was technically and economically evaluated. Two slightly different cases of a larch-based biorefinery were compared to conventional kraft pulping. The wood chips of Larix sibirica (Lebed.) were pre-extracted (PE) and washed with water prior to pulping, in order to generate an additional sugar side-stream. The sugars were hydrolyzed into monosugars, which were then fermented by Bacillus coagulans into lactic acid. The lactic acid needs to be purified before sold to the market. By pulping the pre-extracted wood chips with anthraquinone (AQ) and polysulfide (PS), the pulp yield loss was reduced. The pulp was then bleached (O-D0-Ep-D1-P). The products of this larch biorefinery are bleached softwood pulp and lactic acid. Three process cases were simulated: conventional kraft pulping, PE-PSAQ with 0.5% PS, and PE-PSAQ with 2% PS, in terms of mass and energy balances. Considering the availability of larch resources, this kind of a biorefinery could s...}, number={3}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Horhammer, Hanna S. and Treasure, Trevor H. and Gonzalez, Ronalds W. and Heiningen, Adriaan R. P.}, year={2014}, month={Jan}, pages={1206–1213} }
 @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 $0.65/l, the co-production of cellulosic bioethanol and power does not produce financeable returns. A risk analysis indicates that there is a probability of 26.6% to achieve an internal rate of return equal or higher than 12%. It is suggested that focus be placed on improving yield and reducing CAPEX before this technology can be applied commercially. This modeling approach is a robust method to evaluate economic feasibility of integrated production of bio-power and other products based on extracted hemicellulose.}, journal={Energy Conversion and Management}, publisher={Elsevier BV}, author={Treasure, T. and Gonzalez, R. and Venditti, R. and Pu, Y. and Jameel, H. and Kelley, S. and Prestemon, Jeffrey}, year={2012}, month={Oct}, pages={141–153} }
 @article{santos_treasure_gonzalez_phillips_lee_jameel_chang_2012, title={Impact of hardwood species on production cost of second generation ethanol}, volume={117}, ISSN={["1873-2976"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84861134453&partnerID=MN8TOARS}, DOI={10.1016/j.biortech.2012.04.083}, abstractNote={The present work targeted the understanding of the influence of nine different hardwood species as feedstock on ethanol production yield and costs. It was found that the minimum ethanol revenue (MER) ($ 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{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{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{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{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} }