(551c) Sustainability Metrics and Life-Cycle Assessment for Biochemical Conversion of Corn Stover to Cellulosic Ethanol, Iso-Butanol, and N-Butanol

Aggressive renewable fuel policies will necessitate unprecedented biomass feedstock production and installation of fuel conversion and distribution infrastructure. Conversion technologies have been actively developed and process improvements to these technologies have been investigated with the goal of cost optimization, thus minimizing risk and expediting industry learning. Expansion of the cellulosic biofuels industry at the scale needed to meet the Renewable Fuel Standard goals is also expected to come with some environmental impacts. Hence, the success of the biofuels industry depends not only on economic viability but also on environmental sustainability. Overarching concerns such as the environmental sustainability need to be addressed for sustainable biofuel production. This study quantifies and compares sustainability metrics for the production of cellulosic ethanol, n-butanol, and iso-butanol via biochemical conversion process that utilizes corn stover as feedstock. The quantification and assessment of the sustainable metrics associated with the production of these cellulosic liquid biofuels that include consumptive water use, life-cycle greenhouse gas (GHG) emissions, fossil energy consumption, energy return on investment (EROI), and net energy value (NEV) will be presented and discussed.