Aviation biofuel
The International Air Transport Association (IATA) considers it a key element in reducing the environmental impact of aviation.
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.
[12] Palm oil cultivation is constrained by scarce land resources and its expansion to forestland causes biodiversity loss, along with direct and indirect emissions due to land-use change.
[17] This lessens the need to grow crops specifically for fuel, which in itself is energy intensive and increases CO2 emissions throughout its life cycle.
[21] That year, Boeing was co-chair of the Algal Biomass Organization, joined by air carriers and biofuel technology developer UOP LLC (Honeywell).
[26] Biofuels were approved for commercial use after a multi-year technical review from aircraft makers, engine manufacturers and oil companies.
[28] As of July 2020, seven annexes to D7566 were published, including various biofuel types:[29] In December 2011, the FAA awarded US$7.7 million to eight companies to develop drop-in sustainable fuels, especially from alcohols, sugars, biomass, and organic matter such as pyrolysis oils, within its CAAFI and CLEEN programs.
[40] By 2020, International Airlines Group had invested $400 million to convert waste into sustainable aviation fuel with Velocys.
[41] In early 2021, Boeing's CEO Dave Calhoun said drop-in sustainable aviation fuels are "the only answer between now and 2050" to reduce carbon emissions.
[42] In May 2021, the International Air Transport Association (IATA) set a goal for the aviation industry to achieve net-zero carbon emissions by 2050 with SAF as the key component.
[43] The 2022 Inflation Reduction Act introduced the Fueling Aviation's Sustainable Transition (FAST) Grant Program.
[48] Systems that use synthetic biology to create hydro-carbons are under development: Small piston engines can be modified to burn ethanol.
[70] The United States Air Force found harmful bacteria and fungi in their biofueled aircraft, and use pasteurization to disinfect them.
[71] In 2019 the International Energy Agency forecast SAF production should grow from 18 to 75 billion litres between 2025 and 2040, representing a 5% to 19% share of aviation fuel.
[74] A SAF sustainability certification ensures that the product satisfies criteria focused on environmental, social, and economic "triple-bottom-line" considerations.
[77] Leading airlines and other signatories to the Sustainable Aviation Fuel Users Group (SAFUG) pledged to support RSB as their preferred certification provider.
For example, in the EUTS, SAFUG's proposal was accepted[80] that only fuels certified as sustainable by the RSB or similar body would be zero-rated.
[82][83] In addition to SAF certification, the integrity of aviation biofuel producers and their products could be assessed by means such as Richard Branson's Carbon War Room,[84] or the Renewable Jet Fuels initiative.
[86][verification needed] Along with her co-authors, Candelaria Bergero of the University of California's Earth System Science Department stated that "main challenges to scaling up such sustainable fuel production include technology costs and process efficiencies", and widespread production would undermine food security and land use.
