There are many types of coal, including anthracite, bituminous, subbituminous, and lignite. Anthracite has the highest carbon content. The carbon content is anywhere between 86 and 98 percent. This type of coal is what you might burn in your home. There are 7.3 billion tons of anthracite reserves in the United States, mainly in Pennsylvania.
Bituminous coal is the most plentiful type of coal in the United States.
It is mainly found in the eastern and middle parts of the North American continent. Bituminous coal is primarily used to generate electricity and to make coke for the steel industry. Bituminous coal has a carbon content of 45 to 86 percent and a heat value of 10,500 to 15,500 Btu's per pound. Subbituminous coal ranks just below bituminous coal with 35 to 45 percent carbon content. The heat value of subbituminous coal is between 8,300 and 13,000 Btu's per pound.