A kind of method for preparing halopropanol and propylene oxide

Abstract

The invention provides a method for preparing halogen propanol. The method comprises the following steps (1) halogen alcoholization: adding halogen hydride, H2O2, propylene and an HTS molecular sieve into a reaction device, and carrying out halogen alcoholization reaction to obtain the halogen propanol. The invention also provides a method for preparing epoxypropane with a halogenohydrin method. The method comprises the following steps: (1) halogen alcoholization: adding halogen hydride, H2O2, propylene and an HTS molecular sieve into the reaction device, and carrying out the halogen alcoholization reaction to obtain halogen propanol; (2) saponification: carrying out saponification reaction on halogen propanol and a hydroxide of alkali metal in step (1), and separating to obtain the epoxypropane and alkali halide metal salt; optionally (3) electroosmosis: carrying out bipolar membrane electroosmosis on the alkali halide metal salt obtained in step (2) to obtain the hydroxide of alkali metal and the halogen hydride. According to the methods, the halogen propanol or the epoxypropane can be prepared at extremely high selectivity and yield, and the discharging of waste water and waste residues can be drastically lowered.

Description

technical field [0001] The present invention relates to a method for preparing halopropanol, and a method for preparing propylene oxide from halopropanol; more specifically, it provides a method for preparing halopropanol by using propylene as a raw material and adopting a new halohydrin method, and using a new halohydrin Method for preparing propylene oxide. Background technique [0002] Propylene oxide (hereinafter referred to as PO) is an important organic chemical raw material. As the third largest derivative of propylene series, its biggest application is the preparation of polyether polyols, as well as the production of propylene glycol and nonionic surfactants. In recent years, PO is also widely used in the synthesis of green products such as dimethyl carbonate and carbon dioxide polymer. [0003] The production process of propylene oxide mainly includes chloroalcoholization method, co-oxidation method (also called indirect oxidation method) and direct oxidation met...

AI Technical Summary

Problems solved by technology

[0005] The preparation of propylene 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 dichloropropane

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

In addition, chlorine gas reacts with propylene 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 propylene 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 propylene oxide by the chlorohydrin method produces 40-50 tons of chloride-containing waste water and 2.1 tons of calcium chloride waste. The "five highs" characteristics of high, high COD content and high suspended solids content are difficult to deal with and seriously pollute the environment

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

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