What Are Coal Gasification and IGCC?
In the coal gasification process, coal is heated in the presence of steam, causing some of the hydrogen in the steam to unite with carbon in the coal. This process creates methane (the principal ingredient of natural gas), carbon monoxide, and hydrogen. Coal gasification involves the combustion of some of the carbon in the coal to produce the heat that makes the process work. Byproducts of this carbon combustion are carbon dioxide, ash, and sulfur, all of which may have market value and may be separated for sale (“carbon sequestration”). A “combined cycle” involves use of a gas turbine (“GT”) to generate electricity, with the waste heat from the GT used to raise steam to generate additional electricity via a steam turbine. Where the GT is fired on a gas fuel derived from the gasification of liquid or solid carbonaceous materials, the cycle is known as an integrated gasification/combined cycle, or “IGCC.” IGCCs are able to convert “difficult” liquid and solid fuels to electricity at hig
