Coal is important because it is a reliable and an affordable source of energy in many countries. It is responsible for about 40 percent of the electricity generated in the world. Coal is a crucial ingredient in manufacturing industries.
There are two types of coal: metallurgical and thermal. Thermal coal is used for power generation. The process of power generation involves burning thermal coal that has already been pulverized to powder. The heat produced is then used to transform water into steam. The steam propels a turbine that is connected to an electrical generator, which contains coiled wires that rotate around a magnet, to generate electricity. The generated electricity is then transmitted and distributed through power lines.
Metallurgical coal is mostly used for the production of steel. Coal is also used as a key ingredient in manufacturing petroleum, cement, tar and synthetic rubber. Some useful ingredients that are separated from coal, such as ethylene and methanol, are used for manufacturing fertilizers, plastics and synthetic fibers.
Coal is a fossil fuel formed through geological processes that occurred over millions of years. It is formed from decayed vegetation that is compressed at high temperatures beneath layers of sediment rock and sand. It is usually found in layers known as coal beds or in veins called coal seams.