The pilot plant demonstration process uses coal tar and refinery solvent blended, cleaned and treated to produce the various fractions. In another process aimed at producing jet fuel, they mix raw, clean coal with decant oil the liquid found at the bottom after catalytic cracking and then co-coke. Fuel-grade coke, which is a standard fuel in the steel industry, sells for about $20 a ton. This co-coking process aims to produce coke or carbon of much higher quality usable in manufacturing carbon anodes for a variety of uses. The coke used in these anodes is a much higher value than fuel coke.
"So far the process has produced really good carbon, but it contains too many residual minerals for anode use," says Clifford. "The liquid component does include jet fuel, but the liquid products are very heavy in fuel oil." The researchers report at the American Chemical Society meeting today (Aug. 20), in Boston that future work will strive to reduce impurities in the solid carbon product. Researchers will also investigate either fractionating the fuel oil component or improving the liquid yield.
Another approach to achieving liquid fuels from coal is to extract the liquids from coal using refinery liquid. This method uses light cycle oil to extract the liquid components of coal and then the liquid portion, without separation, travels on through the refinery hydrotreater. In initial bench testing, this method produced a 50 percent yield of liquids. When processed in a multistage reactor, 70 percent extraction took place. The researchers are continuing this work to reduce the amount of light cycle oil necessary, develop a method to separate liquids and solids, and scale up the process.
|Contact: Andrea Elyse Messer|