The main product of coking is metallurgical coke, while gas and aromatic hydrocarbons such as benzene, toluene, xylene and naphthalene are by-products. Coal gasification, the main products are city gas and various fuel gases, as well as synthetic gas; The main products such as low-temperature dry distillation of coal, direct liquefaction of coal and indirect liquefaction of coal are artificial petroleum and liquid chemical products.