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Air Force Flight Test of Syntroleum Gas-to-Liquids Fuel Successful

The test plane takes off from Edwards Air Force Base. (US Air Force photo/Chad Bellay)

Syntroleum announced that its Fischer-Tropsch (FT) jet fuel has been successfully tested in a United States Air Force B-52 Stratofortress Bomber aircraft.

The plane lifted off from Edwards Air Force Base, Calif., with a 50/50 blend of FT and traditional JP-8 jet fuel which was burned in two of the eight engines on the plane. This marks the first time that FT jet fuel has been tested in a military flight demo, and is the first of several planned test flights.

The test is a result of more than four years of successful research and development efforts with the U.S. Department of Defense (DOD), focused on producing a high-performance alternative fuel for military applications.

The program culminating in the test flight today is the first step in opening up new horizons for sourcing fuel for military purposes.

—Bill Harrison, fuels expert with the Air Force Research Laboratory at Wright-Patterson Air Force Base in Ohio

Undersecretary of the Air Force Dr. Ronald M. Sega was on the mission as a crewmember.

This test sets the stage for a more comprehensive plan the Air Force has toward conservation. This test fits into this overall vision and is the first step in a long process for looking at the viability of alternative fuels.

—Dr. Sega

Dr. Sega said the engines running on the synthetic fuel performed as well as the others. But he is still waiting for test analysis and the final test results. The next step in the program will be an eight-engine test in a few months.

Before the manned flight, the Air Force Flight Test Center tested the fuel to see how it reacted to aircraft parts. The fuel ran a T-63 engine during 130 hours of fuel testing. One of the engines was then taken off the B-52 and sent to Tinker Air Force Base, Okla., where it went through a 50-hour continuous alternative fuel run.

The engines were reinstalled into the bomber and ground tested before the test flight.

After going through the testing at Edwards, the alternative fuel left in the bomber’s fuel tanks is scheduled to undergo cold-weather testing in January or February.

The fuel was produced at Syntroleum’s gas-to-liquids (GTL) FT demonstration facility near Tulsa, Okla. where it has produced more than 400,000 gallons of ultra clean products. This flight test is part of the DOD’s Assured Fuel Initiative, an effort to develop secure domestic sources for the military’s energy needs. The Pentagon hopes to reduce its use of crude oil and foreign producers and get about half of its aviation fuel from alternative sources by 2016.

Syntroleum’s 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. In addition to the company’s work with the DOD, Syntroleum’s technology and FT products have been successfully tested in several government programs through the US Department of Energy’s ultra clean fuels program and with academic research institutions and auto manufacturers. One of the shuttle buses used at Edwards Air Force Base is running Syntroleum’s diesel fuel as part of an ongoing road test.

Although the jet fuel used in the B-52 test was produced from natural gas feedstock, the company points out the potential for using coal in the FT process as well.




90% decrease in particulates? Would this restrict the formation of contrails?


Under a carbon cap jet fuel could be made by FT synthesis from feedstocks including natural gas, coal and biomass. Maybe more electricity generation will have to switch to nuclear and renewables to make room for liquid fuels. While I'd guess this jet fuel would be more expensive it could save non-military users such as airlines, tourism and aircraft manufacture from financial ruin under oil depletion.

Hydrogen Fan

I think this is a marvelous achievment. When considering that liquid based carbon fossil fuels are in decline it should be viewed as a landmark step. And with any new technology in its infancy from here on one could expect to see improvements in efficiency as well as reductions in CO2 emissions.


Would this restrict the formation of contrails?

I bit off topic, but that is the way they discovered Global Dimming. After 9/11 when no jets were flying, there were no contrails for the first time. They could make some pure measurements and verify the condition.

Rafael Seidl

Switching jet engines to synfuel will not reduce the formation of contrails as such, as the amount of water vapor emitted is unchanged. However, the reduced PM emissions would impact atmospheric albedo and reduce cloud formation to some extent. The (sensible) reduction of sulphur emissions from power stations and motor vehicles has been tied to reduced aerosol levels. The net effect of aerosols is believed to be moderate global cooling, so cleaner-burning jet fuel might accelerate global warming.

The synfuel to be used by the US armed forces will be derived not from renewable biomass but from domestic coal, much as Germany's was during WW2. This reduces the US air force's dependence on foreign oil but further exacerbates global warming.

Note that synfuel is presently considered too expensive for commercial aviation.


I just threw the issue out, but Aviation Week & Space Technology just had an article on how South African Airways is using a synthetic blend in some of its aircraft. I don't believe they identified any problems, although I don't have the magazine at hand to verify.


If you have been reading this site for a while, you noticed that Sir Richard Branson is investing in cellulosic ethanol and presumably wants to some day use it as fuel for his airline. If I were in the airline or auto industry it would have occured to me long ago that they are dependant on the oil industry as a major supplier and are very vulnerable to price inceases and supply shortages.

Sid Hoffman

SJC, unfortunately the synfuel mentioned in this article is made from natural gas which has fluctuated from $5 to $15 and back to $5 just within the last 24 months alone. Synthetic fuels from biomass may be a little more predictable than from natural gas but they are more expensive too. Either way, I applaud the fact that we're finally researching and applying alternative fuel sources at all, rather than relying 100% on oil.

Roger Pham

Synthetic liquid hydrocarbon can only be a stopgap measure for the current generation of aircraft. Forward-thinking aerospace mfg(s) must be looking at next-gen of jets capable of flying on liquid H2 or liquid CH4(methane) or LNG. Liquid H2 is so light (1/3 the weight of Kerosene for a given BTU heat) that it can cut the amount of fuel energy used by nearly half for a given payload. This is because 1/3 to 1/2 of the gross weight of a jetliner is taken up by fuel weight. This heavy weight causes increase in structural weight and engine weight and hence more fuel weight.

Bob Morgan


Liquid H2 is so light ((1/3 the weight of Kerosene for a given BTU heat) that it can cut the amount of fuel energy used by nearly half for a given payload.

H2 works out lighter in total, even given it's need for insulation/pressurization and all that?

Roger Pham

Yes, Ernie! Foam or fiberglass insulation is all that'll needed for commercial jets that will use most of its fuel in one day. The remaining fuel not consumed at the end of a flight can be pumped back out. Foam and fiberglass are feather-light. No need for pressurization, nor any need for vacuum insulation like in the BMW 7 LH2 super thermos bottle, given the giant size of the fuel tank of a jet in comparison to a small fuel tank of a car.

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