Virent is flying high after earning praise from an arm of the Air Force for a bio jet fuel made from pine tree wood chips.
But it could be years before the biofuel might be used by commercial airlines, an expert said.
Virent, of Madison, and Virdia, based in California, Virginia and Israel, have been working together since January 2011. Virdia's CASE, or cold acid solvent extraction, process transformed pine tree wood chips into sugars, then Virent's BioForming process turned the sugars into jet fuel.
The U.S. Air Force Research Laboratory gave the biofuel high marks.
"This fuel passed the most stringent specification tests we could throw at it (such as thermal stability) under some conditions where conventional jet fuels would fail. This fuel is definitely worth further evaluation," Tim Edwards of the laboratory's fuels branch said in a news release.
The project was funded by the U.S. Department of Energy, the Israeli Ministry of National Infrastructure and the BIRD Foundation, an Israel-U.S. Binational Industrial Research and Development organization.
Virent and Virdia are still early in the testing process for their jet fuel and will likely continue to work together, Virent spokeswoman Kelly Morgan said. "We are in discussions now as to how to move forward," she said.
Jet fuel is kerosene — "the same fuel you burn in a camping lantern" — in a higher-quality version, said Jeff Davis, general manager at Wisconsin Aviation, the fixed base operator at Dane County Regional Airport in Madison. The company provides fueling and maintenance services, charter aircraft and flight instruction.
Rules approved last July by the American Society for Testing of Materials allow for a 50/50 mix of biofuel and kerosene in jet fuel, and there are some bio jet fuels currently available, Davis said.
Lufthansa, of Germany, is one airline that has been testing the bio jet fuel mix.
"This has been moving at light speed for a while now. The aviation industry knows it's coming," Davis said.
But airlines will likely want to see the military use the biofuel first, he added.
"Once the military has established a track record of safe use of this fuel, the engines using it will be torn down and inspected," Davis said. If the results are favorable, and the fuel is "drop-in," meaning it can be integrated with regular jet fuel pumps and equipment, more airlines and operators will support it more, he said.
Virent has been working on gasoline, diesel and jet fuel and chemicals for use in plastics and fibers, all derived from plants instead of petroleum. Virent has experimented with pine tree waste for gasoline and with corn stover for jet fuel but had not tried the wood chips for jet fuel outside the project with Virdia, Morgan said.