coal formation

It forms from the remainings of swamp plant from 300-400 million. Which dead plants became burried in the swamp. Peat slowing decaying plant matter found in bogs, moors, and mustegs. When acidic and anacrobic conditions prevent complete decay. Heat value of peat is very low- compared to coal. Lignite sometimes called "brown coal". Its found in Alaska and some Western States. Low carbon concentration (30%) and low heat value (< 10,000 BTU/lb). Used in electric power generation. Bituminous Coal is most common form of coal. The carbon value is highly variable (45-85%) and heat value ranges from 10,000-15,000 BTU/lb. Anthracite Coal result from the metamorphosis of bituminous coal. The highest carbon content (85-95%) and heat value (15,000 BTU/lb). Low smoke and high heat values make anthracite popular for human heating in the northeastern U.S. Coke primarily used as a heat source in the steel industry. Water, tar, and other volatiles are driven off to leave high carbon fuel. The by-products of coking are collected for energy production.