Method for preparing halohydrin and ethylene oxide

Abstract

The invention provides a method for preparing halohydrin. The method comprises the following steps: 1) halogen alcoholization: halogen hydride, H2O2, ethylene and Zr-containing hetero atoms having a MFI structural molecular sieve are added in a reaction apparatus, and then are subjected to a halogen alcoholization reaction to obtain halohydrin. The invention also provides a method for preparing ethylene oxide by a halogen alcoholization method, which comprises the following steps: 1) halogen alcoholization: halogen hydride, H2O2, ethylene and Zr-containing hetero atoms having the MFI structural molecular sieve are added in the reaction apparatus, and then are subjected to the halogen alcoholization reaction to obtain halohydrin; 2) saponification: halohydrin and hydroxide of alkali metal are subjected to a saponification reaction, then separated to obtain ethylene oxide and alkali halide metal salt; and optionally, 3) electrodialysis: the obtained alkali halide metal salt is subjected to bipolar membrane electrodialysis to obtain the hydroxide of alkali metal and the halogen hydride. The method is used for preparing halohydrin or ethylene oxide with high selectivity and yield, and greatly reduces the discharge of waste water and waste residue.

Description

technical field [0001] The invention relates to a preparation method of haloethanol, and a method for preparing ethylene oxide from haloethanol; more specifically, it provides a method for preparing haloethanol by using ethylene as a raw material and adopting a new haloalcohol method, and a method for preparing haloethanol by using a new haloalcohol method. Ethylene oxide method. Background technique [0002] 2-Chloroethanol (also called "chloroethane") is an important organic solvent and raw material for organic synthesis. It is used in the manufacture of ethylene oxide, synthetic rubber, dyes, medicines and pesticides, and is also used as an organic solvent. Used in the manufacture of ethylene glycol, ethylene oxide, and the synthesis of medicines, dyes, and pesticides. [0003] Ethylene oxide (hereinafter referred to as "EO") is an important organic chemical raw material. It is an organic compound with the chemical formula C2H4O, a toxic carcinogen that was previously ...

AI Technical Summary

Problems solved by technology

[0006] The preparation of ethylene oxide by the chlorohydrin method of the prior art mainly has the following problems: 1. raw material chlorine and ethylene undergo an addition side reaction to generate ethylene dichloride

Dichloroethane is difficult to utilize and wastes a lot of raw materials

In addition, chlorine gas reacts with ethylene to release a large amount of heat, which is concentrated in the reaction vessel, resulting in great production hazards.

②A small amount of oxygen is inevitably entrained in the raw material chlorine gas during the production process. As the reaction proceeds, chlorine gas continuously participates in the reaction, so chlorine gas needs to be continuously replenished, while oxygen cannot participate in the reaction and accumulates in the reaction device continuously. , the oxygen concentration keeps rising, and the reaction releases heat. Oxygen, chlorine, and ethylene exist at the same time, and it is easy to cause an explosion at high temperature.

④The reaction produces a large amount of calcium chloride, which leads to high COD of wastewater and pollutes the environment

⑤ The consumption of water resources is large, and a large amount of waste water and waste residues are produced. The production of 1 ton of ethylene oxide by the chlorohydrin method produces 40-50 tons of chloride-containing waste water and 2.1 tons of calcium chloride waste. The "five high" characteristics of high content, high COD content and high suspended matter content are difficult to handle and seriously pollute the environment

⑥ The hypochlorous acid produced in the production process also seriously corrodes the equipment

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