Science / Medicine : Coal Tried in Diesel Engines

Diesel engines burning finely powdered coal emit only half as many polluting nitrogen oxides as similar engines burning liquid fuels, according to chemical engineer Mark C. Williams of the U.S. Department of Energy’s Morgantown Energy Technology Center in West Virginia. Sulfur oxide emissions are also low, he said, because sulfur-containing compounds in coal can be removed when it is powdered and sulfur oxides in exhaust gases can be removed with catalytic control systems similar to those found on cars.

Nitrogen oxides are formed from nitrogen in the air when fuels are burned at high temperatures. Because the coal that would be used in a diesel engine is in a slurry with water, it burns at lower temperatures than liquid fuels and fewer nitrogen oxides are formed.

The new technology is so promising, Williams said, that the government has contracted with General Electric Transportation Systems to build a coal-fueled locomotive diesel engine within the next two years.