Toluene is used in large quantities as a solvent and high-octane gasoline additive. It is also an important raw material for organic chemicals. However, compared with benzene and xylene obtained from coal and petroleum at the same time, the current output is relatively surplus, so a considerable amount of toluene is used for removal Alkyl to make benzene or disproportionate to make xylene. A series of intermediates derived from toluene are widely used in the production of dyes; medicines; pesticides; explosives; auxiliaries; spices and other fine chemicals. They are also used in the synthetic materials industry. Monochlorobenzyl obtained by side chain chlorination of toluene; dichlorobenzyl and trichlorobenzyl, including their derivatives benzyl alcohol; benzaldehyde and benzoyl chloride (generally also obtained from the phosgenation of benzoic acid), used in medicine; pesticides ; Dyes, especially in perfume synthesis, are widely used. The cyclic chlorination products of toluene are pesticides; medicines; intermediates for dyes. Benzoic acid is obtained by oxidation of toluene, which is an important food preservative (mainly using its sodium salt) and is 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; Acid chloride, etc., used in detergent additives, fertilizer anti-caking additives; organic pigments; medicine; dye production. Toluene nitration produces a large number of intermediates. Many final products can be derived, of which polyurethane products; dyes and organic pigments; rubber additives; medicines; explosives are the most important.
Toluene is mainly produced from crude oil through petrochemical processes. As a solvent, it is used in oils, resins, natural rubber and synthetic rubber, coal tar, pitch, and cellulose acetate. It is also used as a solvent for cellulose paints and varnishes, and as a solvent for photo-making and ink. Toluene is also an important raw material for organic synthesis, especially chlorinated benzoyl and phenyl, saccharin, trinitrotoluene and many dyes. It is also a component of aviation and automobile gasoline. Toluene is volatile and is less likely to react in the environment. Due to the movement of the air, it is widely distributed in the environment, and the water is recirculated intermittently between the air and the water body through rain and evaporation from the water surface, and it may eventually be degraded due to biological and microbial oxidation. Summarizing the average concentration of air in many cities in the world, the results show that the concentration of toluene is usually 112.5-150 μg/m3, which mainly comes from gasoline-related emissions (automobile exhaust gas, gasoline processing)), but also from industrial activities. Of solvent loss and emissions.