Sustainable Aviation Fuels (SAF) from Ethanol: An Integrated Systems Modeling Approach

Abstract

This work explores the economic and environmental opportunities for sustainable aviation fuel (SAF) in the Brazilian sugarcane industry. Brazil was one of the first countries to use biomass fuels for transportation and is currently the 2nd largest producer of the world�s bioethanol. Bioethanol produced from sugarcane can be upgraded to SAF via the American Society for Testing and Materials (ASTM)-certified pathway alcohol-to-jet (ATJ); however, at least two challenges exist for commercial implementation. First, technologies to produce bio-jet fuels cost more than their conventional fossil-based counterparts. Second, there is considerable uncertainty regarding returns on investment as the sugar and ethanol markets have been historically volatile. As such, we propose a new optimization model to inform risk-conscious investment decisions on SAF production capacity in sugarcane mills. Specifically, we propose a linear program (LP) to model an integrated sugarcane mill that can produce sugar, ethanol, or SAF. Then, using historical price data as scenarios, we determine optimal operation at different market scenarios. Based on the relationship between ethanol, sugar, and SAF prices, we show that the integrated sugarcane mill operates in four production regions. Furthermore, through sensitivity studies, we quantify the impact of SAF prices showing a premium SAF price of 2 $ L-1 results in 100% of scenarios favoring SAF production. These results allow us to guide SAF buyers or policymakers by showing the price point for SAF to become attractive for sugarcane mill integration.