@article{reeb_venditti_gonzalez_kelley_2016, title={Environmental LCA and Financial Analysis to Evaluate the Feasibility of Bio-based Sugar Feedstock Biomass Supply Globally: Part 2. Application of Multi-Criteria Decision-Making Analysis as a Method for Biomass Feedstock Comparisons}, volume={11}, ISSN={1930-2126}, url={http://dx.doi.org/10.15376/biores.11.3.6062-6084}, DOI={10.15376/biores.11.3.6062-6084}, abstractNote={Early-stage evaluation of biofuel and bioproduct technologies is extremely complicated and involves many disparate feasibility criteria, including technical, financial, environmental, logistic, legal, social, and other aspects. Problems can arise for decision-makers when evaluating renewable technologies at this early stage due to bias, shifting preferences or priorities, occurrence of trade-offs, and decision-making complexity. Thus, a method is needed for evaluating disparate, typically non-comparable criteria concurrently. In Part 1 of this research, cradle-to-grave environmental LCA was conducted for biomass delivery to a biosugar refinery using Ecoinvent v2.2 data and the TRACI 2 impact assessment method for midpoint impacts. Biomass availability, delivered cost, sugar yield, transportation distance, harvestable months per year, and other aspects of supply chain feasibility were measured for eighteen feedstock biomass types. In Part 2, stochastic multi-attribute analysis (SMAA) was used alongside LCA to develop an environmental preference single-score probability distribution function for feedstock alternatives. Weighted single-scoring and ranking, using multi-criteria decision-making analysis (MCDA), was conducted considering five criteria of biomass supply feasibility: biomass delivered cost, biosugar yield, harvestable months, transport distance, and environmental preference single-score. Corn was shown to cost the most, followed by switchgrass and U.S. primary forest products. Transport distance was found to be highest for residues due to low yield per acre and low covered area. Results of MCDA show that Brazilian eucalyptus and Malaysian empty fruit bunch biomass types were consistently preferred relative to other biomass types. In the U.S., Genera biomass sorghum is most holistically preferred. It is shown that SMAA is helpful for translating LCA data for decision science. It was shown that MCDA can be useful for early-stage biorefinery technology commercialization decision-making, using the novel decision science tool described herein.}, number={3}, journal={BioResources}, publisher={BioResources}, author={Reeb, Carter Walker and Venditti, Richard and Gonzalez, Ronalds and Kelley, Stephen}, year={2016}, month={May}, pages={6062–6084} }
 @article{reeb_venditti_hays_daystar_gonzalez_kelley_2015, title={Environmental LCA and financial analysis to evaluate the feasibility of bio-based sugar feedstock biomass supply globally: Part 1. supply chain analysis}, volume={10}, DOI={10.15376/biores.10.4.8098-8134}, abstractNote={Chemical production from crude oil represents a substantial percentage of the yearly fossil fuel use worldwide, and this could be partially offset by renewable feedstocks such as woody biomass and energy crops. Past techno-economic and environmental analyses have been conducted for isolated feedstocks on a regional or national scope. This study encompasses complete supply chain logistics analysis, delivered cost financial analysis, national availability, and environmental life cycle assessment (LCA) for 18 selected cellulosic feedstocks from around the world. A biochemical conversion route to monomeric sugars is assumed for estimated sugar yields and biosugar feedstock cost analysis. US corn grain was determined to have the highest delivered cost, while rice hulls in Indonesia resulted in the lowest cost of the feedstocks studied. Monomeric sugar yields from literature ranged from 358 kg BDMT-1 for US forest residues to 700 kg BDMT-1 for corn syrup. Environmental LCA was conducted in SimaPro using ecoinvent v2.2 data and the TRACI 2 impact assessment method for mid-point impacts cradle-to-incoming biorefinery gate. Carbon absorption during biomass growth contributed most substantially to the reduction of net global warming potential. Rice hulls and switchgrass resulted in the highest global warming potential, followed closely by corn and Thai sugarcane bagasse. Contribution analysis shows that chemical inputs such as fertilizer use contribute substantially to the net environmental impacts for these feedstocks.}, number={4}, journal={BioResources}, author={Reeb, C. W. and Venditti, R. and Hays, T. and Daystar, J. and Gonzalez, R. and Kelley, Stephen}, year={2015}, pages={8098–8134} }
 @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={Abstract Mandated 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_reeb_gonzalez_venditti_kelley_2015, title={Environmental life cycle impacts of cellulosic ethanol in the Southern U.S. produced from loblolly pine, eucalyptus, unmanaged hardwoods, forest residues, and switchgrass using a thermochemical conversion pathway}, volume={138}, ISSN={0378-3820}, url={http://dx.doi.org/10.1016/J.FUPROC.2015.04.019}, DOI={10.1016/j.fuproc.2015.04.019}, abstractNote={The cradle-to-grave environmental impacts of thermochemical ethanol from loblolly pine, eucalyptus, unmanaged hardwoods, forest residues, and switchgrass biomass feedstocks were determined and compared to gasoline. The Tool for the Reduction and Assessment of Chemical and Other Impacts (TRACI) method was implemented in SimaPro 7.3 to calculate midpoint environmental impacts. Two normalization value sets were used and weighting was performed to produce a single environmental score. Greenhouse gas (GHG) emission reductions of cellulosic ethanol as compared to gasoline were 65%–77%, depending on the biomass feedstock, qualifying these biofuels as cellulosic ethanol under the Renewable Fuel Standards (RFS2). Effects of direct land-use change were significant (~ 18%) and could increase the GHG emissions for switchgrass derived ethanol above the federal GHG reduction thresholds for cellulosic ethanol. The production and use of cellulosic ethanol reduced fossil fuel consumption by between 95% and 97% and by 81% for forest and switchgrass derived ethanol, respectively. Cellulosic ethanol, however, did not reduce all environmental impact categories (e.g., eutrophication, ozone depletion respiratory effects, acidification, and smog) compared to gasoline. The fuel scenario ranking from lowest impact to highest impact consistently remained the same for GHG emissions, fossil fuel use, and the two single weight score analysis methods and was, in ascending order, forest residues with no forest establishment burdens, forest residues with forest establishment burdens, natural hardwood, pine, switchgrass, and finally gasoline. The GHG emission reductions from the use of cellulosic ethanol at the renewable fuel standards mandated production volume of 16 billion gallons of cellulosic ethanol per year by 2020 would result in 9–10 billion metric tonnes of GHG emissions avoided.}, journal={Fuel Processing Technology}, publisher={Elsevier BV}, author={Daystar, Jesse and Reeb, Carter and Gonzalez, Ronalds and Venditti, Richard and Kelley, Stephen S.}, year={2015}, month={Oct}, pages={164–174} }
 @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{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{reeb_hays_venditti_gonzalez_kelley_2014, title={Supply Chain Analysis, Delivered Cost, and Life Cycle Assessment of Oil Palm Empty Fruit Bunch Biomass for Green Chemical Production in Malaysia}, volume={9}, ISSN={1930-2126}, url={http://dx.doi.org/10.15376/biores.9.3.5385-5416}, DOI={10.15376/biores.9.3.5385-5416}, abstractNote={Financial, environmental, and supply chain analyses of empty fruit bunch (EFB) biomass are needed for the development of a sustainable green chemicals industry in Malaysia. Herein, holistic analysis of the supply system and EFB life cycle cradle-to-gate are analyzed in an effort to make recommendations for the commercial-scale collection and delivery of EFB from crude palm oil (CPO) extraction facilities to biorefineries in Malaysia. Supply chain modeling tracked inputs and outputs for financial analysis. The openLCA software was used for life cycle assessment (LCA). Allocation scenarios were used to explore the impact of accounting methodologies on the competitiveness of EFB compared to other feedstocks. Sensitivity analysis on the effect of transportation distance, emission flows, and allocation methods on resulting environmental impacts were conducted. The No Burden, Economic, and Mass allocation scenarios resulted in 17, -2.3, and -265 kg CO2-eq. BD tonne-1 EFB global warming impacts (GW), respectively. Delivered cost for EFB was calculated to be approximately 45 US$ BD tonne-1. Environmental burdens were sensitive to allocation scenario, covered area, and land use change. Delivered cost was sensitive to transport distance, covered area, and yield. It was shown that there is sufficient Malaysia EFB available for between 9 and 28 biorefineries, depending upon the scale of production.}, number={3}, journal={BioResources}, publisher={BioResources}, author={Reeb, Carter Walker and Hays, Tyler and Venditti, Richard A. and Gonzalez, Ronalds and Kelley, Steve}, year={2014}, month={Jul}, pages={5385–5416} }
 @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{reeb_lucia_venditti_2013, title={Novel Screening Technique: Integrated Combinatorial Green Chemistry & Life Cycle Analysis (CGC-LCA)}, volume={8}, ISSN={1930-2126}, url={http://dx.doi.org/10.15376/biores.8.2.1513-1516}, DOI={10.15376/biores.8.2.1513-1516}, abstractNote={The integration of combinatorial green chemistry (CGC), a more benign approach to combinatorial chemistry, with environmental life cycle assessment (LCA) methodologies as an improved process development methodology is discussed. It is expected that the CGC approach will require less labor and result in more globally optimized assay results, leading to more optimized unit process design. The technique utilizes chemical assay stage information to rapidly predict globally optimized process conditions based on techno-economic and LCA indicators. A simplified kraft pulping case study of the application of CGC-LCA is demonstrated herein, but CGC analyses could be applied to virtually any chemical-based project development and implementation project.}, number={2}, journal={BioResources}, publisher={BioResources}, author={Reeb, Carter W. and Lucia, Lucian A. and Venditti, Richard A.}, year={2013}, month={Jan}, pages={1513–1516} }
 @article{daystar_reeb_venditti_gonzalez_puettmann_2012, title={Life-Cycle Assessment of Bioethanol from Pine Residues via Indirect Biomass Gasification to Mixed Alcohols}, volume={62}, ISSN={0015-7473}, url={http://dx.doi.org/10.13073/FPJ-D-12-00025.1}, DOI={10.13073/fpj-d-12-00025.1}, abstractNote={Abstract The goal of this study was to estimate the greenhouse gas (GHG) emissions and fossil energy requirements from the production and use (cradle-to-grave) of bioethanol produced from the indirect gasification thermochemical conversion of loblolly pine (Pinus taeda) residues. Additional impact categories (acidification and eutrophication) were also analyzed. Of the life-cycle stages, the thermochemical fuel production and biomass growth stages resulted in the greatest environmental impact for the bioethanol product life cycle. The GHG emissions from fuel transportation and process chemicals used in the thermochemical conversion process were minor (less than 1 percent of conversion emissions). The net GHG emissions over the bioethanol life cycle, cradle-to-grave, was 74 percent less than gasoline of an equal energy content, meeting the 60 percent minimum reduction requirement of the Renewable Fuels Standard to qualify as an advanced (second generation) biofuel. Also, bioethanol had a 72 percent lower a...}, number={4}, journal={Forest Products Journal}, publisher={Forest Products Society}, author={Daystar, Jesse and Reeb, Carter and Venditti, Richard and Gonzalez, Ronalds and Puettmann, Maureen E.}, year={2012}, month={Jul}, pages={314–325} }