1 Comparative Lifecycle Analysis of BioEnergy Pathways: Cellulosic Ethanol vs Biomass Electricity

This research assesses the comparative environmental profiles of the bioenergy systems- biofuel (ethanol) and biomass electricity- derived from switchgrass. Switchgrass cultivation as a dedicated energy crop is an emerging practice. It has high yield with relatively low nutrient requirements and has a great potential to meet future energy needs. The contribution of this research is twofold. First, the life cycle energy and GHG emissions of individual bioenergy pathways- producing cellulosic ethanol and biomass electricity- are analyzed in greater detail. In contrast with previous studies, we have not just used a single value of input parameters for different life cycle stages, but instead, have assessed the impact based on a probability distribution by incorporating a Monte Carlo analysis. This has helped to address the variability in the lifecycle impacts of bioenergy systems and establishing a range of energy and greenhouse gas (GHG) impacts, rather than previous single-valued estimates. Second, a framework to compare cellulosic ethanol and biomass electricity lifecycle energy and GHG emissions is provided. We propose the criterion for comparison should not be dictated by absolute emissions along a certain bioenergy pathway, such as producing biofuels or biomass electricity. Instead, w