Lipids to biojet and sustainable aviation fuel: uses and competing demands for lipid feedstocks

Abstract The use of biojet and sustainable aviation fuels (SAF) as low carbon‐intensity (CI) fuels is likely to be the primary pathway to decarbonize aviation. ‘Waste lipids’, such as fats, oils, and greases (FOGs), are preferred feedstocks due to their lower CI. However, they are mainly used to make biodiesel or renewable diesel. Therefore, there has been a significant increase in the price paid for “waste lipids” and consequently an increase in their collection. However, due to the limited availability and competition, waste‐lipid/FOG feedstocks are unlikely to meet 2030 demands for biojet or SAF. Consequently, increasing amounts of SAF are produced from higher CI plant‐derived lipids such as soya and rape/canola. Currently, about 20% of the world’s vegetable‐derived lipids are used to make biodiesel or renewable diesel and SAF, with the majority allocated to food and oleochemicals. The rising value and scarcity of waste‐lipid/FOG feedstocks, coupled with competition from both traditional markets (e.g., edible oil, cosmetics) and biofuels has heightened interest in lipid feedstocks. Greater attention will be directed towards the CI of lipids, if the overall objective is to decarbonize the fuel. However, biodiesel/renewable diesel benefits from lower costs, increased yields, and lower CI than biojet/SAF. This will result in increasing competition for lipid feedstocks between the biodiesel, renewable diesel, and biojet/SAF markets.