The US Air Force intends to certificate its entire aircraft fleet to run on synthetic jet-fuel blend by 2011, and began on 8 August when the Boeing B-52H became the first to be approved.

The eight-engined bomber finished testing earlier this year with fuel produced from natural gas using the Fischer-Tropsch (F-T) process.

USAF-b52 
 The eight engine Boeing B-52H was the first to be approved to run on synthetic jet fuel blend

Each time the price of fuel goes up $10 a barrel, it costs the USAF $600 million, says air force secretary Michael Wynne. "It causes angst to know that we're faced with a commodity that some might use against us," he says, pointing to the potential of F-T to convert domestic coal and natural gas to jet fuel.

Shell Houston was recently awarded a contract to provide 1.1 million litres (290,000USgal) of the synthetic fuel, with some bound for NASA test centres. Interest is high in the F-T process, which uses heat, pressure and catalysts to convert carbon-based feedstock into fuel.

The next aircraft to be certificated for synthetic fuel will be the Boeing C-17. "This will be a bridge into the commercial arena," says Wynne, as the airlifter is powered by the same Pratt & Whitney PW2000s that power Boeing 757 airliners.

Afterburning engine tests on the Rockwell B-1 are scheduled for November, says William Anderson, assistant secretary of the air force for installations, environment and logistics.. "The air force will be prepared to award contracts for competitively priced, domestically produced, synthetic fuel following certification of the fleet in early 2011," he says.

The USAF plans to use a 50/50 blend with kerosene in all aircraft by 2016, calling for 1.5 billion litres of synthetic fuel each year. "We are not searching for suppliers at this time as there are no domestic suppliers," says Anderson.

A 10,000 barrel a day plant would require about a $1 billion investment, says Jack Holmes, chief executive of Syntroleum, the Oklahoma-based producer of the synthetic fuel used in the B-52 tests. "That's because of all the coal handling, the coal gasification, which is very expensive."

In July Syntroleum announced it had teamed with Tysons Foods to provide the USAF with 1,900 litres of jet fuel produced from chicken fat using a cheaper and greener method. Starting with animal fats eliminates the first stages of the process. "We can build a 5,000 barrel a day plant for $100 million and we think we can have it on line in less than two years," says Holmes.

 

Source: Flight International