An Assessment of Canadian Corn Ethanol Life Cycle Climate Change Impacts and Potential Mitigation Pathways Including Carbon Capture and Sequestration

Abstract

This thesis is an ethanol GHG life cycle assessment under several scenarios, or Cases. It also evaluates the effects of implementing CCS and biomass combustion at ethanol plants to compare it to other CO2 reduction opportunities. This thesis compares the 2009 CA-GREET “US Dry Mill Average” pathway with three others - an Ontario GREET case, an Ontario GHGenius case, and a site-specific case that substitutes publicly-known Suncor plant data. Life cycle emissions are compared on a “grams of CO2 equivalent per Megajoule of fuel energy provided” basis. Conventional corn-based ethanol can be an effective carbon mitigation strategy if the physical plant, site location and direct emissions are designed correctly. At current production levels, land use change is likely not significant in North America due to availability of sufficient fallow farmland and improving crop yields. Implementing fermentation CCS can abate almost 1 Mt in Canada and 86 Mt worldwide.