Methods for preparing halogenated ethanol and ethylene oxide by dry gas

Abstract

A method for preparing halogenated ethanol by a dry gas is disclosed, and the method comprises the following steps: (1) halohydrination, to be more specific, adding hydrogen halide, H2O2 and the dry gas in a reactor for halohydrination to obtain the halogenated ethanol. A method of producing ethylene oxide by the dry gas is also disclosed, and the method comprises the following steps: (1) halohydrination, to be more specific, adding the hydrogen halide, the H2O2 and the dry gas in the reactor for halohydrination to obtain the halogenated ethanol; and (2) saponification, to be more specific, taking the halogenated ethanol obtained by the step (1) and an alkali metal hydroxide (preferably, sodium hydroxide, potassium hydroxide or lithium hydroxide) for saponification, and separating to obtain the ethylene oxide and a halogenated alkali metal salt. By preparation of the halogenated ethanol from the hydrogen halide, the H2O2 and the dry gas and then saponification, the ethylene oxide can be prepared by extremely-high-selectivity and high-yield use of an ethylene component in the dry gas, and waste water and waste residue discharge is greatly reduced.

Description

technical field [0001] The present invention relates to a method for preparing haloethanol, and a method for preparing ethylene oxide from dry gas; more specifically, it provides a method for preparing haloethanol by using dry gas as a raw material and adopting a new haloalcohol method, and a method for preparing haloethanol by using a new alcohol 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] Epoxides contain epoxy groups, are chemically active, and are easy to ring-opening polymerization. They are important organic chemical raw materials. Ethylene oxide is an important organic chemica...

AI Technical Summary

Problems solved by technology

[0006] The preparation of epoxides by the chlorohydrin method of the prior art mainly has the following problems: 1. raw material chlorine and olefins undergo addition side reactions to generate dichloroalkanes

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

In addition, chlorine gas reacts with olefins, releasing 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 continues to rise, and the reaction releases heat. Oxygen, chlorine, and olefins 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 disadvantage of the chlorohydrin method is that it consumes a lot of water resources and produces a large amount of waste water and waste residue. The chlorohydrin method produces 1t of epoxides and produces 40-50t of chloride-containing waste water and 2.1t of calcium chloride waste residue. The waste water has high temperature and pH The "five highs" characteristics of high value, high chlorine content, high COD content and high suspended solids content are difficult to handle and seriously pollute the environment

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

However, such methods have the inherent problems of the chlorohydrin method

Images