A revised specification issued by standards organization ASTM International establishes requirements for the use of biofuel blends in conventional jet fuel, facilitating wider use of cleaner-burning “renewable” fuels made from plants.

Through new provisions of the standard, “up to 50 percent bio-derived synthetic blending components can be added to conventional jet fuel,” according to ASTM, formerly known as the American Society for Testing and Materials. The synthetic components “are identical to hydrocarbons found in jet fuel” but come from feedstocks containing vegetable oil such as algae, camelina or jatropha, or from animal fats.

John Heimlich, vice president and chief economist with the Air Transport Association of America, described the revised standard as a “critical and significant step which brings the airline industry closer to meeting our environmental goals of widespread production of cleaner, alternative fuels while enhancing energy supply security and competitiveness.”

The revised ASTM D7566-11 standard, approved July 1, already contains criteria for fuel produced from coal, natural gas or biomass using the Fischer-Tropsch process in converting gas to liquid hydrocarbons. ASTM said companies across the fuel supply chain, including renewable fuel producers, aircraft and engine manufacturers and regulatory agencies, participated in the development and revision of the specification. “Because of the great emphasis on safety when you’re dealing with aviation fuel, the (revision of D7566) required a collaborative and cooperative effort between the members of the aviation fuels community,” said Mark Rumizen of the Commercial Aviation Alternative Fuels Initiative.

Airline flight demonstrations using biofuel blends date at least to 2008, and efforts are under way in the U.S., Europe and elsewhere to develop biofuel supply chains. ASTM has created a task force to establish specifications for direct sugar-to-hydrocarbon renewable jet fuels, the subject of another significant, recent development in biofuels. Airframers Boeing and Embraer and the Inter-American Development Bank announced on July 26 that they will jointly fund an analysis of producing renewable jet fuel sourced from Brazilian sugarcane. The study will evaluate the environmental and market consequences of using a jet fuel produced by Amyris, of Emeryville, Calif.

“Collaborative research into the cane-to-jet pathway is important for diversifying aviation’s fuel supplies,” said Billy Glover, Boeing vice president of environment and aviation policy. “With aviation biofuel now approved for use in commercial jetliners, understanding and ensuring the sustainability of sources that can feed into regional supply chains is critical and Brazil has a strong role to play there.”