Coal To Liquid Fuels

Coal-to-Liquids (CTL) (flash movie)
"Clean Coal Technologies" Center for Applied Energy Research

CTL fuel is readily useable today in existing transportation markets and can be delivered through existing pipelines. Auto and airplane engines are currently compatible with CTL fuels

CTL diesel fuel is cleaner than conventional diesel, with virtually zero emissions of criteria pollutants, hazardous air pollutants and mercury. It will rely on coal mined under the most comprehensive environmental laws in the world.

The production of CTL fuels begins with coal as a raw material or feedstock. Both indirect and direct liquefaction processes have been proven.

In indirect coal liquefaction, coal is subjected to intense heat and pressure to create a synthesis gas comprised of hydrogen and carbon monoxide. The synthetic gas is treated to remove impurities and unwanted compounds such as mercury and sulfur. This clean gas enters a second stage Fischer-Tropsch process which converts the synthesis gas into clean liquid fuels and other chemical products.

Diesel fuel produced by Fischer-Tropsch synthesis — virtually sulfur-free with low aromatics and a high cetane value — is cleaner than conventional diesel. It burns more completely and emissions are significantly lower than low-sulfur diesel, as tested by the Department of Defense in 6.5 liter diesel engines. Most of the CO2 is already concentrated and ready for capture and possible sequestration or for use in enhanced oil or gas recovery.

In direct coal liquefaction, coal is pulverized and mixed with oil and hydrogen in a pressurized environment. This process converts the coal into a synthetic crude oil that can then be refined into a variety of fuel products. The direct coal liquefaction technology has been demonstrated in the United States and is now being commercially deployed in China and other countries.