(134b) Sustainability Assessment of Grass to Sustainable Fuel Pathways

The National Renewable Energy Laboratory has pioneered a biorefining process capable of converting methane-forming wet waste into energy-dense hydrocarbons through anaerobic digestion [1]. In our recent study, we leverage this innovation to address reducing greenhouse gas (GHG) emissions within the aviation sector by converting mixed Prairie biomass to Jet fuel. This project is supported by a $80 million USDA Climate Smart Award to demonstrate prairie grass to renewable fuel technologies at the commercial scale. Our approach involves a comprehensive Techno-Economic Analysis (TEA) of utilizing anaerobic digestion (AD) for Sustainable Aviation Fuel (SAF) production, encompassing a multi-step process spanning feedstock selection, biogas production, refinement, and catalytic conversion of biomethane into hydrocarbons, all culminating in the production of aviation-grade fuels [2]. Expanding upon our prior investigations [2], this study advances the analysis by broadening the scope of our Life Cycle Assessment (LCA) to include an array of environmental factors. While our previous research established the minimum fuel selling price in range $30-40 of AD-derived SAF and highlighted a promising Global Warming Potential (GWP) of -0.14 Kg CO2eq/MJ due to greenhouse gas capture, our current work delves deeper into the ecological ramifications of the AD-SAF pathway. This follow-up analysis expands our environmental assessment by integrating a wider range of impact indicators. We now consider factors like acidification, ecotoxicity, eutrophication, and human health effects alongside global warming and air quality concerns. This comprehensive evaluation aims to provide a holistic understanding of the ecological sustainability of AD-SAF production. This knowledge contributes to a more informed discussion about the potential of AD-SAF in fostering a sustainable future for aviation, specifically focusing on the environmental implications of using prairie biomass.