Production method of epoxy chloropropane by hydrogen peroxide method

Abstract

The invention discloses a method for preparing epoxy chloropropane with the oxidation of chloropropene. The chloropropene, a solvent and fine particles of titanium silicate molecular sieve catalyst are put into a reaction pot and a hydrogen dioxide solution is added at 10 DEG C to 80 DEG C. The method is characterized in that a reaction is carried out under a subacidity condition and after the reaction, materials pass through an intermediate tank for oil-water dissociation to be divided into oil phase and water phase; the oil phase is sent into a rectifying tower for separating the chloropropene and ECH. After the water phase is filtered, a catalyst filter cake is washed by the solvent, regenerated or applied to an epoxidation reaction after being directly beat with the solvent. The ECH is extracted from an aqueous layer after filtration by the chloropropene. An extracted oil layer and an oil layer obtained from the separation of a reaction solution are combined and rectified, or the extracted oil layer is applied to the epoxidation reaction; water left from the extraction is rectified for recycling methanol and applied to the preparation of catalysts; and the method has simple procedures, small consumption amount of solvents, high separation yield of reaction products and easy realization of industrialization.

Description

technical field [0001] The present invention relates to the production method of epichlorohydrin, in particular, relates to a method of using titanium silicon molecular sieve as a catalyst and hydrogen peroxide as an oxidant to carry out a slurry bed reaction to catalyze the oxidation of chloropropene to produce epichlorohydrin , belongs to the technical field of organic chemical industry. Background technique [0002] Epichlorohydrin (ECH) is an important bulk organic chemical raw material and fine chemical product. It is the third largest epoxide in output after ethylene oxide and propylene oxide. It is widely used in the synthesis of epoxy resin, Glycerin, chlorohydrin rubber, pharmaceuticals, pesticides, surfactants, glass fiber reinforced plastics, ion exchange resins, coatings and plasticizers, etc. At present, epichlorohydrin is produced from propylene, and the production method is mainly the chloropropene method. The chloropropene method, also known as the high-tem...

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Problems solved by technology

Although this process solves the problems of complex operation and large energy consumption for the preparation of epichlorohydrin due to the introduction of a large amount of methanol solvent, direct use of chloropropene both as a reaction raw material and as a reaction solvent will cause: 1. the molecular sieve catalyst in the liquid phase ( Chloropropene and hydrogen peroxide) have high surface tension and poor dispersion performance. ②It is not conducive to the diffusion of reaction products in the catalyst pores, the catalyst activity decreases rapidly, the service life is short, and the catalyst regeneration frequency and use cost increase; ③The reaction time is long, and some are long Up to 10-20hr, if you want to speed up the reaction speed, you must increase the proportion of allyl chloride, increase the ratio of allyl chloride to hydrogen peroxide, at least 4:1, so it will increase the energy consumption of recovery and separation, and at the same time, allyl chloride The cost of epoxidation accounts for more than 70%. With the same separation and recovery rate of allyl chloride, the increase in the amount of allyl chloride will directly lead to an increase in the cost of epoxidation.

[0010] If you want to maintain the activity of the catalyst and improve the separation yield of ECH, the epoxidation reaction and separation process must be done: ①The temperature of the epoxidation reaction is relatively mild, and the high temperature will cause the decomposition of hydrogen peroxide; ②The epoxidation reaction time should not be too long, Otherwise, side reactions will increase; ③ a certain amount of solvents such as alcohol and ketone should be added to the system to facilitate the diffusion of reaction products in the pores of the catalyst; 50°C) contact to prevent the formation of by-products during the separation process, the generated HCl will cause the stainless steel material of the distillation tower to be easily corroded

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