Solid fuel purposes, such as refining metals. Coal is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. The extraction of coal, its use in energy production and its byproducts are all associated with environmental and health effects including climate change. Variations such as smokeless coal can be formed naturally in the form of anthracite, a metamorphosed type of coal with a very high carbon content that gives off a smokeless flame when set alight. Coke is a fuel with few impurities and a high carbon
Coal gasification has multiple beneficial uses such as aggregate in concrete, aggregate in asphalt for road construction, grit in abrasive blasting, roofing granules, etc. CO is of paramount importance in global climate change. Ash is formed in gasification from inorganic impurities in the coal. Some of these impurities react to form microscopic solids which can be suspended in the syngas produced by gasification. Typically coal contains anywhere from 0.2 to 5 percent sulfur by dry weight, which converts to HS and COS in the gasifiers due to the high temperatures and low oxygen levels. These "acid gases" are removed from the syngas