Cost and carbon intensity implications of coprocessing sustainable aviation fuel at petroleum refineries

Sustainable aviation fuel (SAF) will play a critical role in decarbonizing the aviation industry. Among SAF production pathways, alcohol-to-jet (ATJ) stands out for its scalability, supported by abundant feedstock availability and a well-established bioethanol industry. However, significant reductions in SAF carbon intensity require the use of future feedstocks (e.g., cellulosic) whose adoption is hindered by high capital costs for feedstock processing and ethanol upgrading.

A study by researchers at the University of Illinois Urbana-Champaign evaluated the financial viability and environmental implications of integrating an ATJ SAF biorefinery within a petroleum refinery, utilizing miscanthus and switchgrass as example feedstocks. Three scenarios were evaluated: standalone (benchmark), colocated, and repurposing (coprocessing SAF within the petroleum refinery).

Results showed that repurposing reduces baseline capital costs by 36% and SAF minimum selling price (MSP) by 12% to 8.14 USD·gal^–1; the superior performance of repurposing is consistent across both feedstocks. Integration has a limited effect on SAF carbon intensity, which remains stable across scenarios, whereas using cellulosic feedstocks reduces carbon intensity by over 70% relative to corn, with baseline values of 17.01 g CO₂e·MJ^–1 for miscanthus and 12.23 g CO₂e·MJ^–1 for switchgrass. Global sensitivity analysis reveals MSP declines with greater coprocessing levels.

Overall, this work demonstrates the potential of cellulosic ATJ coprocessing to enable cost-effective, low-carbon aviation fuels.

The lead researchers on this study are part of the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), a Department of Energy (DOE) Bioenergy Research Center, which funded the work with a grant from the DOE Office of Science, Biological and Environmental Research Program.

Images available upon request.