The Economic\nand Environmental Case for Cattle Manure\nand Prairie Grass-Derived Sustainable Aviation Fuel

The aviation sector faces a significant\nchallenge in reducing its\ngreenhouse gas (GHG) emissions to achieve net-zero global CO<sub>2</sub> emissions by 2050. Sustainable aviation fuels (SAF) derived from\nvarious pathways offer a promising alternative to conventional fossil-based\njet fuels. While several SAF pathways are approaching commercialization,\ncost reduction and long-term sustainability remain critical hurdles.\nRecent research has highlighted the potential of anaerobic digestion\n(AD) for SAF production, aligning with a circular economy by repurposing\nwaste materials into valuable energy products. Nonetheless, significant\nchallenges related to scalability, feedstock availability, and refining\ntechnologies hinder the widespread adoption of AD-derived SAF. This\nstudy addresses these challenges by conducting a techno-economic analysis\n(TEA) of SAF production using AD, encompassing a multistep process\ninvolving feedstock selection, biogas production, biogas refinement,\nbiomethane catalytic conversion into hydrocarbons, and final fuel\nrefinement to meet the stringent specifications required for aviation\nfuels. The BioSTEAM modeling tool was utilized to establish the minimum\nfuel selling price (MFSP) of SAF, which is $2.70/L ($10.22/gal). A\nlife cycle assessment (LCA) is also conducted to evaluate the overall\nenvironmental impact of the entire process, considering factors such\nas feedstock sourcing, energy consumption, emissions, and waste management.\nThe global warming potential (GWP) is −260 g of CO<sub>2</sub>e/MJ. Additionally, sensitivity and uncertainty analyses were applied\nto evaluate how variations in process adaptations affect both the\nMFSP and GHG emissions associated with SAF production. This comprehensive\nassessment highlights the potential of AD-derived SAF in contributing\nto a sustainable and circular aviation economy, offering valuable\ninsights into its economic and environmental viability for future\ndevelopment and commercialization.