Comparative Life Cycle Assessment of Sustainable Aviation Fuel Production from Different Biomasses

The aviation sector makes up 11% of all transportation emissions and is considered a "hard to abate" sector since, due to the long distances to be traveled, opportunities for electrification are rather limited. Therefore, since there are no alternatives to fuels, Sustainable Aviation Fuels (SAFs), or fuels produced from biomass, have recently been developed to reduce climate-changing emissions in the aviation sector. Using Life Cycle Assessment, this research evaluated the environmental compatibility of different SAF production routes from seven biomasses: four food feedstocks (Soybean, Palm, Rapeseed, and Camelina), one non-food feedstock (Jatropha curcas L.), and two wastes (Waste Cooking Oil, or WCO, and Tallow). The evaluation was carried out using SimaPro 9.5 software. The results showed that the two potentially most favorable options could be Camelina and Palma, as they show minimal environmental impacts in 4 and 7 out of 18 impact categories, respectively. Soybean, on the other hand, appears to be the least sustainable precursor. Considering GWP, SAF production could reduce the values compared to fossil fuel by 2.8-3.6 times (WCO), 1.27-1.66 times (Tallow), 4.6-5.8 times (Palm), 3.4-4.3 times (Jatropha), 1.05-1.32 times (Rapeseed), and 4.36-5.5 times (Camelina), demonstrating the good environmental impact of these pathways. Finally, the sensitivity analysis showed that SAF production from waste could be an environmentally friendly option, with rather low environmental impacts, in the range of 5.13 g CO2 eq/MJ for Tallow and 3.12 g CO2 eq/MJ for WCO. However, some of the energy would have to come from sustainable energy carriers such as biomethane and renewable sources such as photovoltaic energy.