Treatment method and system of byproduct hydrochloric acid in chlorination process of toluene or chloro-toluene

Abstract

The invention discloses a treatment method and system of the byproduct hydrochloric acid in the chlorination process of toluene or chloro-toluene. The byproduct hydrochloric acid produced by a tolueneor chloro-toluene chlorination system enters an extraction tower from the top of the extraction tower, the extractant enters the extraction tower from the bottom of the extraction tower, the hydrochloric acid and the extractant make countercurrent contact with each other in the extraction tower, the extractant absorbs the organic matter in the byproduct hydrochloric acid, and is extracted out from the top of the extraction tower, the raffinate is extracted out from the bottom of the extraction tower, and is fed into the lower part of a carbon fiber adsorption tower, the carbon fiber adsorbs the extractant from the raffinate, after adsorption, the hydrochloric acid purification products, the raffinate, reaches the industrial grade, and is discharged from the top of the carbon fiber adsorption tower into a storage tank; when the carbon fiber penetrates, the carbon fiber adsorption tower is desorbed by water vapor, the high temperature water vapor containing extractant enters a condenserfor condensation, the condensate enters the extraction tank for oil and water separation, the recovered oil is returned to the extraction tower. According to the method, the byproduct hydrochloric acid is treated and reaches the quality requirement of industrial grade, resources are saved, the circular economy development is realized, and environment is protected.

Description

technical field [0001] The invention relates to the field of recovery, utilization and treatment of by-products in the chemical production process, in particular to a treatment method and system for by-product hydrochloric acid in the chlorination production process of toluene or chlorotoluene. Background technique [0002] In the chlorination industry, especially in the production process of toluene and chlorotoluene chlorination, a large amount of by-product hydrogen chloride (HCl) will be produced. Most of these chlorine gases absorb by-product hydrochloric acid with water, because of containing a certain amount of organic impurities, toluene and chlorotoluene, It does not meet the industrial requirements, and its use is greatly limited. In some areas, it is even discharged directly after neutralization with alkali, which not only affects the economic benefits of chlorine product production, but also causes waste of resources and pollutes the environment. This method is no...

AI Technical Summary

Problems solved by technology

[0002] In the chlorination industry, especially in the production process of toluene and chlorotoluene chlorination, a large amount of by-product hydrogen chloride (HCl) will be produced. Most of these chlorine gases absorb by-product hydrochloric acid with water, because of containing a certain amount of organic impurities, toluene and chlorotoluene, It does not meet the industrial requirements, and its use is greatly restricted. In some areas, it is even discharged directly after neutralization with alkali, which not only affects the economic benefits of chlorine product production, but also causes waste of resources and pollutes the environment. This method is no longer sustainable.

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