(704b) Life Cycle Assessments of Pyrolysis-Based Biofuels From Diverse Biomass Feedstocks

Matt Mihalek¹, Jiqing Fan¹, Gaurav Bhardwaj¹, Kyle Andrews¹, Robert Handler², Tom Kalnes³, David Shonnard^1,2

1 Department of Chemical Engineering, Michigan Technological University, Houghton, MI

2 Sustainable Futures Institute, Michigan Technological University, Houghton, MI

3 UOP LLC (Honeywell), Des Plaines, IL

Abstract

Renewable hydrocarbon biofuels are being investigated as possible alternatives to conventional fossil fuels like gasoline, kerosene and diesel.  Feedstocks such as corn stover, sugarcane bagasse, switchgrass, waste wood, and algae, are being evaluated as candidates for pyrolysis and upgrading to drop-in hydrocarbon fuels. This research is developing preliminary life cycle assessments (LCA) for each feedstock and comparing the greenhouse gas (GHG) emissions of the hydrocarbon biofuels to current fossil fuels. As a comprehensive study, this analysis attempts to account for all of the emissions associated with each feedstock through the entire life cycle. Emissions from all stages including feedstock production, land use change, pyrolysis, stabilizing the pyrolysis oil for transport and storage, and upgrading the pyrolysis oil to a hydrocarbon fuel are included. In addition to GHG emissions, the energy requirements and water use have been evaluated over the entire life cycle.  The goal of this research is to help rank the feedstocks and the resultant hydrocarbon biofuels based on three environmental indicators; GHG emissions, energy demand, and water utilization.  Preliminary results indicate that liquid hydrocarbon biofuels produced through this pyrolysis-based pathway can achieve greenhouse gas emission savings of greater than 50% compared to petroleum fuels, thus qualifying these biofuels under the US EPA RFS2 program.