Sustainable Aviation Fuel: Progress, Challenges, and Opportunities

The aviation industry accounts for 2.8% of the global greenhouse gas (GHG) emissions in 2020 and these emissions are expected to dramatically grow as the passenger numbers doubles from 2016 to 2035. To mitigate the expected increase, the International Air Transport Association (IATA) set a cap on the amount of CO2 emissions in 2020, and a 50% reduction by 2050 compared to 2005. There are various options in the aviation sector to reduce GHG such as alternative fuels, renewable fuels, and aircraft electrification. Renewable aviation fuels (RAFs) offer a way to turn different feedstocks like agriculture residues, municipal waste, and other organic substances into biofuels for aviation. Even though in recent years the demand for new fuels has been slow, reaching 150 million liters in 2020, it is expected to reach 65 billion liters by 2050 due to the increase in carbon reduction policies. In this poster, we review the seven different technology pathways approved by the American Society for Testing and Materials (ASTM) to produce RAF: Fischer Tropsch Synthetic Paraffin Kerosene (FT-SPK), Fischer Tropsch with added aromatics (FT-SPK/A), Alcohol-to-Jet (ATJ-SPK), Hydroprocessed Esters and Fatty Acids (HEFA-SPK), Hydro processing of Fermented Sugars (HFS-SIP), Catalytic Hydrothermolysis Synthetic (CHJ-SPK), and Hydrocarbon-Hydroprocessed Esters and Fatty Acids (HC-HEFA-SPK). Today, there are only 25 refineries in operation that implement only 4 of these technologies (FT, HEFA, ATJ, & CHJ). We compare two metrics – the minimum jet fuel selling price (MJSP) and CO2 emissions – across these technologies to understand the slow adoption.