Toluene is mainly made from crude oil through petrochemical process. As a solvent, it is used in oil, resin, natural rubber and synthetic rubber, coal tar, asphalt, cellulose acetate, as a solvent for cellulose paint and varnish, as well as for photographic plate making and ink. Toluene is also an important factor in organic synthesis, especially for benzoyl chloride and phenyl, saccharin, trinitrotoluene and many dyes

Materials. It is also a component of aviation and automotive gasoline. Toluene is volatile and not easy to react in the environment. Due to the movement of air, it is widely distributed in the environment, and through rain and evaporation from the water surface, it can be recycled between the air and water body, and eventually be degraded by biological and microbial oxidation. The average concentration of toluene in the air of many cities in the world is summarized. The results show that the concentration of toluene is usually 112.5-150 μ g / m3, which mainly comes from gasoline related emissions , as well as solvent loss and emissions caused by industrial activities.  

Toluene is widely used as solvent and additive of high octane number gasoline. It is also an important raw material of organic chemical industry. However, compared with benzene and xylene obtained from coal and petroleum at the same time, the current production of toluene is relatively surplus. Therefore, a considerable amount of toluene is used for dealkylation or disproportionation to produce xylene. A series of intermediates derived from toluene are widely used in the production of fine chemicals such as dyes, pharmaceuticals, pesticides, explosives, auxiliaries, spices and so on, and also used in the synthetic materials industry. Benzyl chloride, dichlorobenzyl chloride and Trichlorobenzene, including their derivatives benzyl alcohol, benzaldehyde and benzoyl chloride (also obtained from the phosgenation of benzoic acid), are widely used in the synthesis of pharmaceuticals, pesticides, dyes, especially perfumes. The product of cyclization of toluene is the intermediate of pesticide, medicine and dye. Benzoic acid is produced by oxidation of toluene, which is an important food preservative (mainly using its sodium salt), and also used as an intermediate in organic synthesis. Intermediates prepared by sulfonation of toluene and benzene derivatives, including p-toluenesulfonic acid and its sodium salt; CLT acid; toluene-2,4-disulfonic acid; benzaldehyde-2,4-disulfonic acid; Toluenesulfonyl chloride, etc., which are used in detergent additives, fertilizer anti caking additives; organic pigments; medicine; dyes production. A large number of intermediates were prepared by nitration of toluene. Many final products can be derived, among which polyurethane products, dyes and organic pigments, rubber additives, medicine, explosives and other aspects are the most important.