Biofuels are biomass-derived fuels from plants, animals, or waste; depending on which type of biomass is used, they could lower CO2 emissions by 20–98% compared to conventional jet fuel.[4] The first test flight using blended biofuel was in 2008, and in 2011, blended fuels with 50% biofuels were allowed on commercial flights. In 2023 SAF production was 600 million liters, representing 0.2% of global jet fuel use.[5]
Aviation biofuel can be produced from plant or animal sources such as Jatropha, algae, tallows, waste oils, palm oil, Babassu, and Camelina (bio-SPK); from solid biomass using pyrolysis processed with a Fischer–Tropsch process (FT-SPK); with an alcohol-to-jet (ATJ) process from waste fermentation; or from synthetic biology through a solar reactor.
SAF technology faces significant challenges due to feedstock constraints. The oils and fats known as hydrotreated esters and fatty acids (Hefa), crucial for SAF production, are in limited supply as demand increases. Although advanced e-fuels technology, which combines waste CO2 with clean hydrogen, presents a promising solution, it is still under development and comes with high costs. To overcome these issues, SAF developers are exploring more readily available feedstocks such as woody biomass and agricultural and municipal waste, aiming to produce lower-carbon jet fuel more sustainably and efficiently.[7]
Aviation biofuel is mostly a distraction. Any serious effort to decarbonize the transportation industry would focus on a scalable system, presumably high-speed rail.
(And whoever is thinking about being a smartass, don’t you dare come at me with bullshit about trans-ocean flights, they obviously can’t be take by train, but biofuel is still utterly incapable of supplying even only ocean flights. It’s not ever going to be a viable product. We’d be better off trying to scale up carbon capture than try to use all our arable land to grow crops for fuel.)
They talk about blends which is interesting.