The US Department of Defense is examining the possible role of Fischer-Tropsch fuels for military vehicles, starting with its aircraft.
The Defense Energy Support Center of Fort Belvoir, Va., which oversees fuel purchases for DOD, has asked companies to submit proposals regarding the availability of possible synthetic fuel suppliers for anticipated field tests by the Air Force and Navy.
Last year, the Air Force successfully tested a synthetic fuel in a B-52 bomber. The test flights involved a 50-50 blend of traditional jet fuel and a synthetic liquid made from natural gas using the Fischer-Tropsch process.
William E. Harrison III, the chief of fuels branch propulsion directorate for the Air Force Research Laboratory, said DOD wants to obtain for the military clean fuels that are produced from secure domestic resources.
“It’s a 40-year-old airplane with very dirty engines,” Harrison said of the B-52, adding that the aircraft was chosen to test new technology fuel because its engine enables convenient comparison of engine performance using different fuels.
The Air Force seeks to replace its commercial airlines Jet-A fuel and its kerosene-based JP-8, which is the equivalent of the Navy’s F-76. Both the military and airlines are considering whether alternative fuels could help reduce costs in times of high oil prices.
Speaking in The Woodlands, Tex., last year at a conference on carbon dioxide, Harrison said Fischer-Tropsch fuel produces lower emissions compared with traditional fossil-based fuel. Test results indicated the synthetic fuel produced 1.6% fewer CO2 emissions, 50-90% less particulate matter, and no sulfur.
“CO2 has got to be part of the strategy,” he said. “America’s unconventional fuel resources can help bridge the gap to future fuels.”
Secure supply
Military preparedness requires secure fuel sources, Harrison said, adding that the military is looking to reduce its dependence on imported crude oil. The Fischer-Tropsch process can use coal, natural gas, or biological matter-all abundant in the US-to make an intermediate synthesis gas (syngas) that is refined into fuel.
Syntroleum Corp. of Tulsa made the synthetic liquid from natural gas for the B-52 test flights. The Air Force eventually wants a synthetic liquid produced from coal.
The Air Force spends more than $10 million/day on fuel, Harrison said, adding that every $10/bbl increase in oil prices means an additional $600 million/year to the Air Force’s fuel bill.
“Fischer-Tropsch is not just for the airplane...Fischer-Tropsch is a very fine rocket fuel,” he said. “The Air Force and the Department of Defense are serious about alternative fuels.”
DOD has looked at the experience of the South African military because Sasol Ltd. has produced synthetic fuel from coal for at least a decade, he noted.
“Actually if you fly in and out of Johannesburg on a commercial airline, you are going to get some fuel that has Fischer-Tropsch [produced fuel] in it,” Harrison said.
The US Air Force has 150 different variations of aircraft along with ground support equipment and vehicles, he said. Testing of engines other than the B-52 is planned.
DOD is collaborating with engine manufacturers and is soliciting comment from energy companies about supplying alternative fuels, Harrison said. DOD’s goal is to have a single kind of fuel, although it wants to have as many suppliers as possible.
“We want to see diversity of technology,” Harrison said. “We don’t tell the refiners how to refine it. We tell them the standards. That’s the path we are going down. We like to see diversity.”
Biofuel
The military also is looking into using vegetable oil from a variety of agricultural feedstocks for making aviation fuel via the Fischer-Tropsch process.
DOD’s Defense Advanced Research Projects Agency awarded $5 million to the Energy & Environmental Research Center at the University of North Dakota in Grand Forks for the development and demonstration of a renewable domestic jet fuel.
The 18-month project was announced in December 2006. The fuel produced by the EERC would be a candidate with which to replace the traditional JP-8 fuel.
EERC spokesmen said the center will expand its capabilities in tactical fuels and demonstrate how fuels made from crop oil could replace imported oil.
“Our whole approach with this project is to develop an affordable new fuel that can be dropped in to replace the current JP-8 fuel,” said Ted Aulich, EERC senior research manager. “This replacement will allow an easy transition from a petroleum-based fuel to a 100% domestic renewable fuel.”
