US airforce successfully tests synthetic (bio)fuel in B52 aircraft

We have been tracking developments in aviation biofuels for quite a while (earlier post and references there). The creation of renewable fuels for large aircraft that fly at high altitudes is the last frontier, with many challenges remaining. But today, the US airforce announced that it has come a step closer to making renewable aviation fuels a reality: a B-52 Stratofortress took off on december the 15th on a flight-test mission using a blend of synthetic fuel and JP-8 (kerosene) in all eight turbine engines. This is the first time a B-52 has flown using a synfuel blend as the only fuel on board.

Synthetic fuels are obtained from gasifying a renewable (biomass) or non-renewable (coal, natural gas) primary energy source to obtain a carbon and hydrogen rich gas. This gas is then liquefied by Fischer-Tropsch synthesis, a process which results in clean 'synthetic fuels' (click diagram). If such synfuels are based on fossil fuels ('coal-to-liquids' or 'gas-to-liquids') without the carbon that gets released during the gasification being captured and sequestered, then they contribute substantially to climate change. If the synfuels on the contrary are based on renewable biomass ('biomass-to-liquids'), they offer a very clean kind of carbon-neutral fuel.

The gas-to-liquids process as it has been developed by Syntroleum, a Fischer-Tropsch technology leader whose fuel was used in a previous airforce test, is indifferent to the type of syngas used. This means syngas derived from biomass remains a very promising resource for the production of ultra-clean synfuels.

Syntroleum’s synthetic jet fuel has shown superior performance characteristics compared to traditional aviation fuels. Prior testing by the military on the company’s FT fuels have shown a reduction in particulate matter and soot emissions of greater than 90% depending upon the turbine engine type compared to aviation fuels produced by refining crude oil. The reduced particulate matter and soot emissions significantly improve engine efficiency, performance and overall air quality.

Commenting on yesterday's test, Secretary of the Air Force Michael W. Wynne, said:
biomass :: bioenergy :: biofuels :: energy :: sustainability :: gas-to-liquids :: coal-to-liquids :: biomass-to-liquids :: Fischer-Tropsch :: synfuels :: synthetic fuels :: aviation ::

"The B-52 test flights at Edwards Air Force Base are the initial steps in the Air Force process to test and certify a synthetic blend of fuel for its aviation fleet. We are confident that the success of this flight will bring us one step closer to allowing a domestic source of synthetic fuel to accomplish the Air Force mission in the future."

The flight further demonstrates the Air Force's commitment to using alternate fuels and is the next step in the testing and certification process before the fuel can go into widespread use, officials said. According to William Anderson, assistant secretary of the Air Force for installations, environment and logistics, the Air Force has reinvigorated its energy strategy which is underpinned by supply-side availability and semand-side conservation. "The Air Force is moving forward in its commitment to certify alternative sources of fuel for both its aircraft and ground vehicles fleet," said Mr. Anderson.

Maj. Gen. Curtis Bedke, Air Force Flight Test commander, is flying the aircraft to assess how well the aircraft performs using the synthetic blend of fuel. The next test phase for the B-52 will be cold-weather testing to determine how well the synfuel-blend performs in extreme weather conditions.

Earlier, the Argentinian airforce successfully tested a 'bio-jetfuel' consisting of 80% kerosene and 20% of a special type of biodiesel, in a C-130 Hercules cargo carrier (earlier post).

The news is important because it means biomass can now be used in all transport sectors, including aviation, which can not be serviced by any other renewable energy source. This major advantage will no doubt promote the global biomass industry.