Five bio-based jet fuels have been authorized for use for air travel, now that the FAA has announced approval of a new fuel created from an alcohol that is derived from renewable feed stocks.
The newest fuel is known as Alcohol to Jet Synthetic Paraffinic Kerosene (ATJ-SPK). It is created from an alcohol called isobutanol, produced from renewable feed stocks such as sugar, corn, or forest wastes, the agency said in an April 14 news release.
“In contrast to traditional petroleum-based fuels, these new alternative fuels can reduce air quality emissions and are renewable,” the FAA said.
The agency collaborates with the aviation industry to approve alternative aviation fuels through the standards-setting organization ASTM International. The FAA-industry Continuous Lower Energy, Emissions and Noise (CLEEN) partnership was crucial in completing the necessary steps to support ASTM International’s approval of the new fuel, which “could reduce greenhouse gas emissions on a life-cycle basis by up to 85 percent,” the FAA said.
The FAA emphasized that as more alternative jet fuels emerge from development, they have increased potential “for cost-competitive production and broad use.”
Another priority is that the new fuels be suitable for use directly in existing aircraft without modification to engines or other equipment, while maintaining “an equivalent level of safety and performance to petroleum jet fuels.”
Other alternative fuels that have been approved include synthesized iso-parafins (SIP) that "converts sugars into jet fuel"; hydro-processed esters and fatty acids synthetic paraffinic kerosene (HEFA-SPK), "which uses fats, oils and greases"; Fischer-Tropsch Synthetic Paraffinic Kerosene (FT-SPK), and Fischer-Tropsch Synthetic Kerosene with Aromatics (FT-SKA), both of which use “various sources of renewable biomass such as municipal solid waste, agricultural wastes and forest wastes, wood and energy crops.”
The new fuels are being used primarily by airlines, but could eventually enter use in the light-jet sector.