Life-Cycle Assessment of Biofuels
The project is creating a comprehensive framework for assessing both the benefits and potential costs of biofuel technologies in terms of environmental quality, human health, natural resources, and local, regional and global economies. Researchers are studying air and water quality, land use, and human health and ecological impacts that arise from the life cycle of biofuels — from biomass growing through fuels production and distribution to fuels use.
We are focused on two specific case studies: (1) Lignin utilization tradeoffs for biochemical lignocellulosic biorefineries, and (2) Life-cycle cost and environmental assessment of drop-in fuels and lubricants produced via fermentation (ABE, ethanol, and 2,3-butanediol) and furan pathways. The completed lignin utilization project focused on the tradeoffs associated with different strategies including on-site combustion for heat and power, export to offsite coal power plants, co-location with coal-fired power plants, and variations on the sizing of natural gas-fired combined head and power units for the lignin-export scenarios. Collaborations with other EBI groups integrated LCA and optimization with novel chemistry. We also plan to complete a life-cycle assessment of the ABE fermentation, chemical catalysis, and upgrading process for diesel fuel production.
The goal of this project is to further establish EBI’s leadership in biofuels life-cycle assessment (LCA) by linking LCA models to chemical process models and basic conversion research. Establishing this connection will provide insight into the cost, energy, and environmental tradeoffs associated with variations in process technology and management of co-products. In 2013 and 2014, we are focusing on two specific case studies: 1) lignin utilization tradeoffs for biochemical lignocellulosic biorefineries, and 2) life-cycle cost and environmental assessment of an ABE chemical catalysis process to produce drop-in fuels, as well as non-ABE variations.
The LCA research team has continued to update the EBI LCA Tool with the latest results from the scientific literature and EBI research. The goal of the EBI LCA Tool is to be able to analyze various biomass-to-biofuel scenarios. Analysis of biofuels at unit as well as regional or national scales are important. We have published a study with six U.S. land-use scenarios for growing Miscanthus in the United States in order to meet the second-generation biofuel mandate by 2020, highlighting the importance of soil-carbon fluxes and biorefinery electricity offset credits. The lessons learned from the study have informed our progress with an energy cane-to-ethanol environmental assessment.
We completed a study showing that the E10 clean air mandate and blend wall have resulted in millions of tons of unnecessary CO2 emissions and billions of dollars of avoidable costs because Midwestern corn ethanol was sent to the coastal states before the local Midwestern markets had become saturated with ethanol. We also published a study on intake fractions of primary conserved air pollutants emitted from on-road vehicles in the United States, providing models and data needed to assess human exposures to air pollutants with a very high level of spatial resolution.
Researchers have continued to improve the biofuel life-cycle analysis (LCA) model. They created the first version of an Excel-based biofuel-specific LCA tool. This tool addresses many of the systematic challenges that were identified in their widely cited “Grand Challenges” paper. In particular, the LCA tool has been able to capture a level of spatial resolution of impacts/costs that has not been addressed in any life-cycle impact study for transportation fuels. When finished, the tool will be able to assess the environmental footprint of a broad range of biofuels.
Researchers completed and demonstrated a computer-based decision support tool to conduct life-cycle assessments of various biofuels and baseline fuels for comparison. This tool addresses carbon footprint, human health burdens, water footprint, and life-cycle external costs that accrue from each of the biofuel life stages, from feedstock production to fuel use. The group has identified seven grand challenges that must be confronted when assessing the relative sustainability of alternative biofuel feedstocks, pathways and products.
Published in 2014
Role of Lignin in Reducing Life-Cycle Carbon Emissions, Water Use, and Cost for United States Cellulosic Biofuels, C. D. Scown, A. A. Gokhale, P. A. Willems, A. Horvath, T. E. McKone, Environmental Science & Technology, V. 48 (15), pp. 8446-8455, July 2, 2014.
Published in 2013
Achieving Deep Cuts in the Carbon Intensity of U. S. Automobile Transportation by 2050: Complementary Roles for Electricity and Biofuels, Corinne D. Scown, Michael Taptich, Arpad Horvath, Thomas E. Mckone, William W. Nazaroff, Environmental Science & Technology, doi: 10.1021/es4015635, July 2013
Published in 2012
Intake Fractions of Primary Conserved Air Pollutants Emitted From On-Road Vehicles in the United States, Agnes B. Lobscheid, William W. Nazaroff, Michael Spears, Arpad Horvath, and Thomas E. McKone, Atmospheric Environment, http://dx.doi.org/10/1016/j.atmosenv.2012.09.027, September 2012 online.
Greenhouse Gas Emissions from the Construction, Manufacturing, Operation and Maintenance of US Distribution Infrastructure for Petroleum and Biofuels, Bret Strogan, Arpad Horvath, Journal of Infrastructure Systems, Il doi:10.1061/(ASCE)15.1943-555X.0000130, September 28, 2012.
Fuel Miles and the Blend Wall: Costs and Emissions from Ethanol Distribution in the United States, Bret Strogan, Arpad Horvath, Thomas E. McKone, Environmental Science and Technology, doi: 10.1021/es204547s, April 16, 2012.
Global Intraurban Intake Fractions for Primary Air Pollutants from Vehicles and Other Distributed Sources, Joshua Apte, Emilie Bombrun, Julian Marshall, William Nazaroff, Environmental Science and Technology, doi: 10.1021.es204021h, March 20, 2012.
Life-Cycle Greenhouse Gas Implications of U.S. National Scenarios for Cellulosic Ethanol Production, Corinne Scown, William Nazaroff, Umakant Mishra, Bret Strogen, Agnes Lobscheid, Eric Masanet, Nicholas Santero, Arpad Horvath, Thomas McKone, Environmental Research Letters, 7(1), doi: 10.1088/1748-9326/7/1/014011, January 24, 2012.
Published in 2011
Water Footprint of U.S. Transportation Fuels, Corinne Scown, Arpad Horvath, Thomas E. McKone, Environmental Science & Technology, 45 (7), pp. 2541-2553, doi: 10.1021/es102633h, March 15, 2011.
Grand Challenges for Life-Cycle Assessment of Biofuels, Tom McKone, William Nazaroff, Peter Berck, Maximilian Auffhammer, Tim Lipman, Margaret Torn, Eric Masanet, Agnes Lobscheid, Nicholas Santero, Umakant Mishra, Audrey Barrett, Matt Bomberg, Kevin Fingerman, Corinne Scown, Bret Strogen, Arpad Horvath, Environmental Science and Technology, DOI: 10.1021/es103579c, January 11, 2011.