Clean process for preparing epoxy chloropropane by zero discharge glycerin method

Abstract

The invention relates to a method for preparing epoxy chloropropane by glycerin, in particular to a clean process for preparing epoxy chloropropane by a zero discharge glycerin method. The clean process is characterized in that glycerin and HCl generate substitution reaction to generate dichloropropanol; NaOH is added into dichloropropanol for cyclization reaction to generate epoxy chloropropane; high-salinity wastewater generated by the reaction is decomposed into HCl and NaOH through bipolar membrane electrodialysis; HCl and NaOH are respectively recycled and generate the substitution reaction and the cyclization reaction with glycerin and dichloropropanol, so that cyclic utilization is realized, and the high-salinity wastewater is not discharged. The clean process provided by the invention has the advantages that the substitution reaction between glycerin and HCl, the cyclization reaction between dichloropropanol and NaOH, and the bipolar membrane electrodialysis decomposition of a NaCl aqueous solution are integrated, the clean production of epoxy chloropropane by the glycerin method is realized, the zero discharge is achieved, the environment is not polluted, and an application potential is huge.

Description

technical field [0001] The invention relates to a method for preparing epichlorohydrin from glycerin, more particularly to a clean process for preparing epichlorohydrin by a zero-emission glycerol method. Background technique [0002] Epichlorohydrin is an important organic chemical raw material and fine chemical intermediate, mainly used in the production of epoxy resin, reinforced resin, water treatment resin, etc. In recent years, more and more epoxy resins have been used in electronics, automobiles, aerospace and other industries, resulting in an increasing demand for epichlorohydrin. [0003] At present, epichlorohydrin is mainly produced by high-temperature chlorination of propylene, which mainly includes high-temperature chlorination of propylene to prepare chloropropene, chloropropene and hypochlorous acid to synthesize dichloropropanol, and dichloropropanol to synthesize epichlorohydrin. responses. The process produces 40-50 tons of high-salt wastewater per ton of...

AI Technical Summary

Problems solved by technology

[0007] In addition to high salinity, epichlorohydrin production wastewater also contains organic matter, which is difficult and expensive to treat. It is one of the most difficult wastewater to treat in the world.

At present, the method of salt production by evaporation is mainly used in industry, but the salt produced contains a large amount of organic matter, which is difficult to sell and becomes solid waste; the dilution biochemical method will waste a lot of water resources, and this process often leads to salt deposition in biochemical systems, Cause sludge performance deterioration and other phenomena

With the increasingly stringent environmental protection requirements, the treatment of epichlorohydrin wastewater has become an unfavorable factor restricting the development of enterprises, affecting the construction of new enterprises, and even affecting the production of established enterprises.

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