Jeffrey Decker reports on the experiments that could find a synthetic alternative to oil-based aviation fuels.
In a few days the final report on synthetic fuel tests will be released by the U.S. Air Force, but already hopes are high after a series of successful flights using jet fuel made from natural gas.
The military and airlines are putting much faith in the technology to succeed oil, as costs per barrel are lingering at record prices and as unhindered distribution from the Middle East and Russia remains uncertain.
Every airliner that fuels up at the Johannesburg airport uses a synthetic blend, and the Germans used the Fischer-Tropsch process extensively during World War II when their oil supplies were cut off. Fischer-Tropsch, sometimes called Coal-To-Liquids or Gas-To-Liquids, used heat and pressure to convert the state of carbon-based and of fossil fuels. Places like the U.S. may not have enough oil to meet demand, but they do have lots of coal, natural gas, shale oil and tar sands.
It’s getting a lot of attention from investors, airlines and scientists, including some from the Air Transport Association.
THINKING
“The current thinking is the emissions are fewer with synthetic fuel at the point of consumption, so the issue is the point of production where you have to sequester the carbon dioxide, which makes it a cleaner burn for the plane or the car,” says John Heimlich, chief economist of ATA. “What probably needs to happen is some congressional package to construct these plants, which I understand can cost $3 or $4 billion. That's the hurdle, the production costs.” A subsidy package is currently starting its journey through US Congress.
The Tulsa, Oklahoma facility that provided 100,000 gallons of jet fuel for the Air Force tests at $20/gallon has been mothballed, says Syntroleum President Gary Gamino. “There wasn’t any economic reason to keep it open. We can’t afford to keep it running just for fun.”
Testing was fun at times, according to the pilots, who pushed a B-52 on a 50 percent blends through several maneuvers, including throttle burst and transients. “That’s sort of the technical term to say, ‘Let’s see if we can abuse the engines and make them cough, sputter and flame out,” said Paul Bollinger, special assistant to the assistant secretary for installation, environment and logistics.
The first test was in September. The first running all eight engines was in December, and then they flew it to Minot Air Force Base in North Dakota for cold weather testing where temperatures ranged from -22 C° to -11.6°C.
“The verdict is: the aircraft started as expected, just like it did on JP-8,” reports Bill Harrison, chief of the Fuels Branch of the Turbine Engine Division Propulsion Directorate Air Force Research Laboratory. At Minot Air Force Base in North Dakota
“They did different tests each day,” Harrison says, “They did some pneumatic starts and some cartridge starts.” No fuel flow problems were detected. At Minot the eight-engined B-52 didn’t leave the ground like it did at Andrews Air Force base.
The fuel left in the tanks was drained for materials testing and auxiliary power unit tests. NB: The B-52 has no afterburner.
“We’re going to get into that probably in fiscal ‘08 with some preliminary work later in this year.”
The technology will grow, if only to meet the U.S. Air Force plans to certify the entire stratofortress fleet for synthetic fuel by 2010. Harrison says he speaks with “Airlines and oil companies, coal companies, venture capitalists” who all are watching the tests. “If you had a commercial scale operation in the U.S., they would probably be producing at market price.
Source: Flight Daily News