29 March 2006

Coal-based jet fuel ready for takeoff

Jet fuel derived from at least 50% coal and comparable to Jet A or military JP 8 has successfully powered a helicopter jet engine.

"Because the fuel is 50% derived from coal, it could reduce our use of imported petroleum for this purpose by half," said Dr. Harold H. Schobert, professor of fuel science and director of Penn State's Energy Institute. "We have shown in tests that the mix can go to at least 75% coal."

Schobert said they can produce the fuel, called JP900, by using light cycle oil, which is a petroleum byproduct, and coal-derived refined chemical oil, a byproduct of the coke industry. The researchers mix the two components and add hydrogen. When distilled, jet fuel comes off as a distillate. The process can occur in existing refineries with some retrofitting, and small amounts of the leftover components will feed into various portions of the petroleum stream. The lighter portions will go to the pool of chemicals that make gasoline, and the heavier ones go to the diesel or fuel oil streams.

"The combustion tests showed that JP900 meets or exceeds almost all specifications for JP8 and Jet A," Schobert said.

These tests showed JP900 has a flash point higher than required for JP8, a lower viscosity and freezing point, and a higher smoke point. The coal-based fuel is lower in aromatics, compounds like benzene and toluene, than conventional jet fuels and is almost sulfur free. From an energy point of view, JP900 produces almost exactly the same Btu as JP8.

Not only does JP900 meet most of the specifications for JP8, it also has the high flash point required of JP5, naval jet fuel, and the thermal stability of JP7, a high performance fuel.

Originally, this project began to develop jet fuel for the next generation of high performance aircraft that would require very thermally stable fuels. Now that fuel prices have soared, officials are now looking at the tests to lower fuel costs, develop secure fuel sources, and decrease dependence on foreign oil.

"The fact that our fuel is almost dead on to JP8 is something that the Air Force likes," Schobert said. "This fuel was intended to be a high heat sink fuel, which it is, but it can also be used in existing engines."

The project now targets coal-based replacement for existing fuels with the hope that this will interest both commercial and military users. So far, the Penn State project has produced 500 gallons of fuel in a pilot plant operated by Intertek of Warren, Pa.

Schobert is now looking to produce about 4,500 gallons, or about 100 barrels, of the fuel for future testing.

For related information, go to www.isa.org/productivity.