USAF trials biofuel in F22 fighter


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State of the art jet aircraft successfully completes supersonic flight on a biofuel blend
It's not only on land that governments and industry are looking to cut carbon emissions, but in the air as well.
The US Air Force alternative fuels program has taken a leap forward with an F-22 Raptor fighter (pictured) reaching supersonic speeds burning a 50:50 blend of conventional petroleum-sourced JP-8 (Jet Propellant 8) and a biofuel extracted from the camelina sativa plant.
Gizmag reports the aircraft reached supercruise (supersonic flight without using the afterburner) speeds of up to Mach 1.5 at 40,000 feet amid a series of air starts, operability and performance manoeuvres altitudes of up to 40,000 feet.
The program is aimed at replacing 50 per cent of the USAF's fossil-sourced aviation fuel with alternatives by 2016.
The fuel is one of a number of blended biofuels called hydrotreated renewable jet fuels (HRJs) sourced from a number of plant oil and animal oils.
HRJs are now well enough proven for the USAF to approve their use unrestricted across its fleet of C-17 Globemaster III transport planes. The program stands a good chance of expanding with the success of the F-22 flight. The aircraft "performed flawlessly on the biofuel blend citing no noticeable differences from traditional JP-8," Jeff Braun, director of the Air Force's Alternative Fuels Certification Division, said in a statement.
Camelina sativa is an oil plant related through the mustard family to canola. It demonstrates many of the cultivation benefits needed to make biofuel viable: it grows fast and needs little water or fertilizer. And while it can't be consumed by humans, it can by livestock, including poultry. This means the 'meal' left over after oil has been extracted from its seed doesn't go wasted.
Camelina-sourced fuel is not new -- European airlines have been experimenting with it for some years. Virgin Atlantic and KLM have both run demonstration flights in 747s using a 50:50 mix of biokerosene and conventional fuel.
Beyond the aviation industry, the biofuel offers potential applications in future hybrid-drive vehicles powered by gas-turbine engines (which are jet engines) -- the Jaguar C-X75 concept pointing the way forward for this type of technological development