Coking factory

A coking factory or a coking plant is where coke and manufactured gas are synthesized from coal using a dry distillation process. The volatile components of the pyrolyzed coal, released by heating to a temperature of between 900°C and 1,400 °C, are generally drawn off and recovered. There are also coking plants where the released components are burned: this is known as a heat recovery process. A layer of ash then forms on the surface of the resulting coke.^[1] The degassing of the coal gives the coke a highly sought-after porosity. The gases are broken down by fractional condensation into hydrocarbon tars, sulfuric acid, ammonia, naphthalene, benzol, and coke gas; these products are then purified in further chemical reactors. Germany still has five coking plants in operation (as of 2010) to meet the needs of its domestic industry.^[2]

Coke is mainly used to produce cast iron in blast furnaces, which remains its main use today. Degassing considerably reduces its sulfur content, enabling the iron and steel industry to produce higher-quality cast iron with lower emissions. Apart from this, coke ash has more or less the same composition as ordinary hard coal.^[3]