@article{pires_williams_daystar_sagues_lan_venditti_2024, title={Evaluating Cotton Apparel with Dynamic Life Cycle Assessment: The Climate Benefits of Temporary Biogenic Carbon Storage}, volume={19}, ISSN={["1930-2126"]}, DOI={10.15376/biores.19.3.5074-5095}, abstractNote={Static life cycle assessment (LCA) methodologies fail to consider the temporal profiles of system inputs and outputs (including emission timing), such that they underestimate the benefits of temporarily stored biogenic carbon in bioproducts, such as cotton. This research focuses on greenhouse gas emission timing and applies dynamic emission accounting to the life cycle of cotton woven pants. The significance of temporary biogenic carbon storage and emission timing is illustrated by converting the 2017 Cotton Incorporated static LCA to a dynamic model using the Dynamic Carbon Footprinter (baseline scenario). A reduction in cumulative radiative forcing for dynamic relative to static modeling of 22%, 5%, and 2% are observed at 10-years, 30-years, and 100-years, respectively. Alternative scenarios analyzed include converting cotton woven pants at end of life to bioenergy, to compost, or to building insulation, an alternative cotton production scenario using regenerative agricultural practices, and two pants extended lifetime scenarios. The regenerative agricultural practice scenario provides reductions in cumulative impacts compared to the baseline scenario of 96%, 69%, and 105% after 10, 30, and 100-years, respectively. A 3x extension in the lifetime of pants provides a benefit in reduced cumulative impacts of 31%, 40%, and 41%, after 10, 30, and 100-years, respectively. This case study with cotton demonstrates that dynamic LCA is a useful tool for assessing the benefits of biobased products, and it allows for more nuanced analysis of reductions in climate impacts in both the short- and long-term time horizons.}, number={3}, journal={BIORESOURCES}, author={Pires, Steven T. and Williams, Allan and Daystar, Jesse and Sagues, William Joe and Lan, Kai and Venditti, Richard A.}, year={2024}, month={Aug}, pages={5074–5095} } @article{kounina_daystar_chalumeau_devine_geyer_pires_sonar_venditti_boucher_2024, title={The global apparel industry is a significant yet overlooked source of plastic leakage}, volume={15}, ISSN={["2041-1723"]}, DOI={10.1038/s41467-024-49441-4}, abstractNote={Abstract Plastic pollution is a global environmental threat with potentially irreversible impacts on aquatic life, ecosystems, and human health. This study is a comprehensive assessment of the global apparel industry’s contribution to plastic pollution. It includes plastic leakage of packaging and end-of-life apparel waste in addition to fiber emissions during apparel production and use. We estimate that the apparel industry generated 8.3 [4.8–12.3] million tons (Mt) of plastic pollution in 2019, corresponding to 14% [5.5%–30%] of the estimated 60 Mt from all sectors. In this study, we demonstrate that the main source of plastic pollution from the apparel supply chain is synthetic clothing as mismanaged waste either in the country of its original use or in the countries receiving used apparel exports. A fundamental transformation of the apparel economy towards a circular framework and decreased synthetic apparel consumption is needed to tackle apparel-related plastic pollution.}, number={1}, journal={NATURE COMMUNICATIONS}, author={Kounina, Anna and Daystar, Jesse and Chalumeau, Sophie and Devine, Jon and Geyer, Roland and Pires, Steven T. and Sonar, Shreya Uday and Venditti, Richard A. and Boucher, Julien}, year={2024}, month={Jun} } @article{smith_zambrano_ankeny_daystar_pires_pawlak_venditti_2024, title={Aquatic Aerobic Biodegradation of Commonly Flushed Materials in Aerobic Wastewater Treatment Plant Solids, Seawater, and Lakewater}, volume={19}, ISSN={["1930-2126"]}, url={http://dx.doi.org/10.15376/biores.19.1.1150-1164}, DOI={10.15376/biores.19.1.1150-1164}, abstractNote={Microfibers and microplastics originating from wastewater treatment plant (WWTP) effluents are significant pollutants in freshwater sources and marine environments. This research investigated the biodegradation of cotton microfibers generated from bleached cotton jersey knit fabric and commercially available flushable wipes, polypropylene-based (PP) nonwoven wipes containing a cellulose component, and tissue paper. Biodegradation was tested in wastewater treatment plants (WWTP) solids, seawater, and lakewater according to the ISO 14852 and ASTM D6691 standard methods in an ECHO respirometer. Degradation experiments continued until a plateau in CO2 emissions was reached, and the final biodegradation extent was calculated relative to the theoretical CO2 produced based on elemental analysis. The results showed that the cotton and other cellulosic materials/components biodegrade to a great extent, as expected for all conditions, whereas the PP did not degrade. In general, for the cellulose polypropylene composite wipes, the cellulose biodegraded readily; the presence of the PP did not hinder the cellulose biodegradation.}, number={1}, journal={BIORESOURCES}, author={Smith, Madilynn M. and Zambrano, Marielis and Ankeny, Mary and Daystar, Jesse and Pires, Steven and Pawlak, Joel and Venditti, Richard A.}, year={2024}, month={Feb}, pages={1150–1164} } @article{zambrano_pawlak_daystar_ankeny_venditti_2021, title={Impact of dyes and finishes on the aquatic biodegradability of cotton textile fibers and microfibers released on laundering clothes: Correlations between enzyme adsorption and activity and biodegradation rates}, volume={165}, ISSN={["1879-3363"]}, DOI={10.1016/j.marpolbul.2021.112030}, abstractNote={The presence and biodegradability of textile microfibers shed during laundering or use is an important environmental issue. In this research, the influence of common textile finishes on the persistence of cotton fibers in an aerobic aquatic environment was assessed. The biodegradation of cotton knitted fabrics with different finishes, silicone softener, durable press, water repellent, and a blue reactive dye was evaluated. The rate of biodegradation decreased with durable press and water repellant finishing treatments. In terms of the final extent of biodegradation, there was no significant difference between the samples. All samples reached more than 60% biodegradation in 102 days. The biodegradation rates were in agreement with observed trends of the same samples for cellulase mediated hydrolysis and cellulase adsorption experiments, indicating the finishes impact the initial adsorption of enzymes excreted by the microorganisms and the initial rates of biodegradation, however despite this the cellulosic material maintains its biodegradability.}, journal={MARINE POLLUTION BULLETIN}, author={Zambrano, Marielis C. and Pawlak, Joel J. and Daystar, Jesse and Ankeny, Mary and Venditti, Richard A.}, year={2021}, month={Apr} } @article{zambrano_pawlak_daystar_ankeny_goller_venditti_2020, title={Aerobic biodegradation in freshwater and marine environments of textile microfibers generated in clothes laundering: Effects of cellulose and polyester-based microfibers on the microbiome}, volume={151}, ISSN={0025-326X}, url={http://dx.doi.org/10.1016/j.marpolbul.2019.110826}, DOI={10.1016/j.marpolbul.2019.110826}, abstractNote={The aerobic biodegradation of common textiles that shed microfibers during laundering was evaluated under the action of microbes found in the environment, such as lake and seawater, and activated sludge at a low concentration from a wastewater treatment plant (WWTP). Under these conditions, the biodegradation potential was the same in all the experiments: Microcrystalline Cellulose (MCC) > Cotton > Rayon > Polyester/Cotton ≫ Polyester. Nevertheless, for cotton and rayon yarns, >70% biodegradation was achieved with activated sludge at low concentration and lake water, whereas in seawater, about 50% degradation was reached. Polyester did not appreciably degrade. The biodegradation results herein indicate potential not absolutes in nature. The bacterial diversity analyses in the different biodegradation inoculums show that there are distinct bacterial communities related to the assimilation and mineralization of complex carbohydrates that were promoted with the cellulosic MCC, cotton, and rayon samples different than the polyester sample.}, journal={Marine Pollution Bulletin}, publisher={Elsevier BV}, author={Zambrano, Marielis C. and Pawlak, Joel J. and Daystar, Jesse and Ankeny, Mary and Goller, Carlos C. and Venditti, Richard A.}, year={2020}, month={Feb}, pages={110826} } @article{zambrano_pawlak_daystar_ankeny_venditti_2021, title={Impact of dyes and finishes on the microfibers released on the laundering of cotton knitted fabrics}, volume={272}, ISSN={0269-7491}, url={http://dx.doi.org/10.1016/j.envpol.2020.115998}, DOI={10.1016/j.envpol.2020.115998}, abstractNote={The influence of common textile finishes on cotton fabrics on the generation of microfibers during laundering was assessed. Microfiber release was determined to be in the range of 9000–14,000 particles per gram of cotton fabric. Cotton knitted fabrics treated with softener and durable press generate more microfibers (1.30–1.63 mg/g fabric) during laundering by mass and number than untreated fabric (0.73 mg/g fabric). The fabrics treated with softener generated the longest average microfiber length (0.86 mm), whereas durable press and water repellent treatments produced the shortest average microfiber length (0.62 and 0.63 mm, respectively). In general, the changes in the mechanical properties of the fibers and fabrics due to the finishing treatments are the main factor affecting the microfiber release. The abrasion resistance of the fabrics decreases for durable press treatments and water repellent treatments due to the brittleness in the structure originated by the crosslinking treatment. In the case of the softener treatment, the fabric surface is soft and smooth decreasing the friction coefficient between fibers favoring the fibers loosening from the textile and resulting in a high tendency for fuzz formation and microfiber release. These findings are useful for the textile industry in the design and selection of materials and treatments for the reduction of synthetic or natural microfiber shedding from textiles.}, journal={Environmental Pollution}, publisher={Elsevier BV}, author={Zambrano, Marielis C. and Pawlak, Joel J. and Daystar, Jesse and Ankeny, Mary and Venditti, Richard A.}, year={2021}, month={Mar}, pages={115998} } @article{zambrano_pawlak_daystar_ankeny_cheng_venditti_2019, title={Microfibers generated from the laundering of cotton, rayon and polyester based fabrics and their aquatic biodegradation}, volume={142}, ISSN={0025-326X}, url={http://dx.doi.org/10.1016/j.marpolbul.2019.02.062}, DOI={10.1016/j.marpolbul.2019.02.062}, abstractNote={The effect of fiber type (cotton, polyester, and rayon), temperature, and use of detergent on the number of microfibers released during laundering of knitted fabrics were studied during accelerated laboratory washing (Launder-Ometer) and home laundering experiments. Polyester and cellulose-based fabrics all shed significant amounts of microfibers and shedding levels were increased with higher water temperature and detergent use. Cellulose-based fabrics released more microfibers (0.2–4 mg/g fabric) during accelerated laundering than polyester (0.1–1 mg/g fabric). Using well-controlled aquatic biodegradation experiments it was shown that cotton and rayon microfibers are expected to degrade in natural aquatic aerobic environments whereas polyester microfibers are expected to persist in the environment for long periods of time.}, journal={Marine Pollution Bulletin}, publisher={Elsevier BV}, author={Zambrano, Marielis C. and Pawlak, Joel J. and Daystar, Jesse and Ankeny, Mary and Cheng, Jay J. and Venditti, Richard A.}, year={2019}, month={May}, pages={394–407} } @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={AbstractIn 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{rajagopalan_venditti_kelley_daystar_2017, title={Multi-attribute uncertainty analysis of the life cycle of lignocellulosic feedstock for biofuel production}, volume={11}, ISSN={1932-104X 1932-1031}, url={http://dx.doi.org/10.1002/BBB.1737}, DOI={10.1002/bbb.1737}, abstractNote={AbstractLife cycle assessments (LCAs) have become a common tool for measuring the environmental performance of various products and processes. This study reviewed the life cycle of lignocellulosic biomass feedstock‐based (pine, eucalyptus, and switchgrass) ethanol biofuels and compared the results to gasoline. Uncertainty analysis of the cradle‐to‐wheel results was conducted using a pedigree matrix method to address uncertainty of life cycle inventory items. A tool called stochastic multi‐attribute analysis for life cycle impact assessment (SMAA‐LCIA) was used to interpret the results generated from the LCA. The normalized results showed that gasoline had high environmental impacts in categories such as carcinogenics and global warming, followed by switchgrass. But the use of a single‐score metric indicated that all bio‐based feedstocks had similar environmental performance, all significantly better than gasoline. The SMAA‐LCIA results showed that when all impacts were weighted equally, the preference from highest to lowest was for loblolly pine, eucalyptus, gasoline, and switchgrass. This rank order switched when differing weighting schemes of Producer, User, and LCA Expert were used. Overall, this method highlights the trade‐offs associated with the selection of different feedstocks and improves the comparison of overall results amongst fuel sources, which can then be more clearly presented to a decision‐maker. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd}, number={2}, journal={Biofuels, Bioproducts & Biorefining: BIOFPR}, publisher={Wiley}, author={Rajagopalan, N. and Venditti, R. and Kelley, S. and Daystar, J.}, year={2017}, month={Mar}, pages={269–280} } @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_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{hubbe_ayoub_daystar_venditti_pawlak_2013, title={Enhanced absorbent products incorporating cellulose and its derivatives: A review}, volume={8}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84887162529&partnerID=MN8TOARS}, DOI={10.15376/biores.8.4.6556-6629}, abstractNote={Cellulose and some cellulose derivatives can play vital roles in the enhancement of the performance of absorbent products. Cellulose itself, in the form of cellulosic fibers or nano-fibers, can provide structure, bulk, water-holding capacity, and channeling of fluids over a wide dimensional range. Likewise, cellulose derivatives such as carboxymethylcellulose (CMC) have been widely studied as components in superabsorbent polymer (SAP) formulations. The present review focuses on strategies and mechanisms in which inclusion of cellulose – in its various forms – can enhance either the capacity or the rate of aqueous fluid absorption in various potential applications.}, number={4}, journal={BioResources}, author={Hubbe, M. A. and Ayoub, A. and Daystar, J. S. and Venditti, R. A. and Pawlak, J. J.}, year={2013}, pages={6556–6629} } @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{lippke_puettmann_johnson_gustafson_venditti_steele_katers_taylor_volk_oneil_et al._2012, title={Carbon Emission Reduction Impacts from Alternative Biofuels*}, volume={62}, ISSN={0015-7473}, url={http://dx.doi.org/10.13073/12-00021.1}, DOI={10.13073/12-00021.1}, abstractNote={Abstract The heightened interest in biofuels addresses the national objectives of reducing carbon emissions as well as reducing dependence on foreign fossil fuels. Using life-cycle analysis to evaluate alternative uses of wood including both products and fuels reveals a hierarchy of carbon and energy impacts characterized by their efficiency in reducing carbon emissions and/or in displacing fossil energy imports. Life-cycle comparisons are developed for biofuel feedstocks (mill and forest residuals, thinnings, and short rotation woody crops) with bioprocessing (pyrolysis, gasification, and fermentation) to produce liquid fuels and for using the feedstock for pellets and heat for drying solid wood products, all of which displace fossil fuels and fossil fuel–intensive products. Fossil carbon emissions from lignocellulosic biofuels are substantially lower than emissions from conventional gasoline. While using wood to displace fossil fuel–intensive materials (such as for steel floor joists) is much more effec...}, number={4}, journal={Forest Products Journal}, publisher={Forest Products Society}, author={Lippke, Bruce and Puettmann, Maureen E. and Johnson, Leonard and Gustafson, Richard and Venditti, Richard and Steele, Philip and Katers, John F. and Taylor, Adam and Volk, Timothy A. and Oneil, Elaine and et al.}, year={2012}, month={Jul}, pages={296–304} } @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} }