The pyrolysis of biomass, such as corn stover, can produce a bio-oil which can then be upgraded into diesel and gasoline using petrochemical refining technology. In addition to using a renewable feedstock, this pyrolysis process has the advantages of employing existing fuel refining, delivery, and end use infrastructure. A life cycle assessment (LCA) totaling environmental flows was performed on the corn stover pyrolysis process, from the production of the feedstock to the end use in a vehicle. The LCA used data from a corn stover E85 ethanol process¹, a National Renewable Energy Laboratory (NREL) wood pyrolysis AspenPlus model², as well as data and analysis from pyrolysis, hydrotreating, and hydrocracking runs by UOP LLC, Pacific Northwest National Laboratory, and NREL. The results from the LCA of the pyrolysis process will be compared to LCAs of a corn stover E85 ethanol process and a gasoline process. This LCA also shows that the production of corn stover is a particularly resource intensive step, with most of the greenhouse gas emissions resulting from this step. Additional life cycle inventory results will be presented, along with the assumptions and methodology used to complete the LCA.

¹Sheehan, J.; Aden, A.; Riley, C. Corn Stover Life Cycle Analysis. NREL/FY01-220. Golden, CO: National Renewable Energy Laboratory, December 2000.

²Putsche, V. Pyrolysis Process Design: Costs and Modeling. NREL/FY04-545. Golden, CO: National Renewable Energy Laboratory, March 2004.