Life Cycle Performance of Cellulosic Ethanol and Corn Ethanol from a Retrofitted Dry Mill Corn Ethanol Plant

摘要: This study conducts a life cycle assessment of simulated dry mill corn ethanol facility in California’s Central Valley retrofitted to also produce from stover, cellulosic feedstock. The examines three designs, all producing and wet distiller’s grains solubles as co-product: baseline with no retrofit, small capacity for stover feedstock, large Corn grain is supplied by rail the Midwest, while sourced in-state farms delivered truck. Two feedstock supply scenarios are considered, testing harvest rates at 25 or 40 % mass. Allocation required separate impacts attributable co-products. Additional explored assess effect co-product allocation methods on results two fuel products, ethanol. tracks greenhouse gas (GHG) emissions, energy consumption, criteria air pollutants, direct water consumption. GHG intensity produced designs range between 61.3 68.9 g CO2e/MJ, which includes 19.8 CO2e/MJ indirect land use change Midwestern grain. varies 44.1 109.2 14.6 32.1 low high cases, respectively. Total input ranges 0.60 0.71 MJ/MJ 0.13 2.29 variability result (a function rate) decisions.