Process for producing benzene, methylbenzene and xylene from crude benzene

Abstract

The invention discloses a process for producing benzene, methylbenzene and xylene from crude benzene. Various impurities, mainly containing thiophene, in the crude benzene are all removed by use of a low-temperature hydrogenation method, wherein all the sulfides (such as thiophene, methylthiophene and carbon disulfide) are converted into H2S and low carbon hydrocarbons, the nitrides are converted into NH3 and arenes or alkanes, the oxides are converted into H2O and arenes or alkanes, and the unsaturated hydrocarbons are saturated by hydrogenation; and next, the impurities are removed by virtue of conventional rectification and extraction rectification. As a result, the benzene, the methylbenzene and the xylene all having good quality can be produced.

Description

technical field [0001] The invention relates to the technical field of crude benzene reprocessing, in particular to a process for preparing benzene, toluene and xylene from crude benzene. Background technique [0002] Benzene is one of the important petrochemical basic raw materials, which can be used in a series of important chemical products such as synthetic rubber, synthetic resin, synthetic fiber, medicine, pesticide, explosive and dyestuff. At the same time, it can also be used as a solvent for paint and rubber; in the oil refining industry, benzene is an admixture to increase the octane number of gasoline. The technical level and output of benzene production have become one of the important symbols to measure the development level of a country's petrochemical industry. [0003] There are currently six sources of benzene: catalytic reforming, pyrolysis gasoline, toluene disproportionation, toluene hydrodealkylation, coke oven light oil, and coal tar. Among them, cata...

AI Technical Summary

Problems solved by technology

[0007] With the development of my country's economy, the import volume of triphenyl (benzene, toluene, xylene) and its downstream products is increasing. Although my country's benzene production reached a record 3.0611 million tons in 2005, it is far from satisfying the nearly 800 domestic In addition, the equivalent consumption of p-xylene in my country has reached 8.45 million tons, while the domestic supply is only about 2.4 million tons, which can only meet 28% of the demand.