Chloropropene oxidation method

Abstract

The invention provides a chloropropene oxidation method. The method comprises the following steps: under oxidation reaction conditions, a liquid mixture comprising chloropropene and an oxidant flows through a catalyst bed layer. The catalyst bed layer comprises a first catalyst bed layer and a second catalyst bed layer. With the flow direction of the liquid mixture as a standard, the first catalyst bed layer is positioned upstream of the second catalyst bed layer. The titanium silicalite molecular sieve loaded in the first catalyst bed layer is hollow titanium silicalite molecular sieve. The titanium silicalite molecular sieve loaded in the second catalyst bed layer is a titanium silicalite molecular sieve different from the hollow titanium silicalite molecular sieve. When the method provided by the invention is used for oxidizing chloropropene, during a long-time continuous running process, a relatively stable oxidant conversion rate and a relatively high target oxidation product selectivity can be obtained. Especially, with the method provided by the invention, epoxide selectivity is high, such that subsequent separation purification difficulty is reduced.

Description

technical field [0001] The invention relates to a method for oxidizing propylene chloride. Background technique [0002] Epichlorohydrin (Epichlorohydrin, abbreviated as ECH), also known as 1-chloro-2,3-epoxypropane, commonly known as epichlorohydrin. There are epoxy groups and active chlorine in the ECH molecule, which is chemically active. The epoxy resin made from ECH has the characteristics of strong adhesion, corrosion resistance to chemical media, low shrinkage, good chemical stability, and high impact strength. [0003] Epichlorohydrin is an important and widely used organic chemical raw material and fine chemical product. Synthetic glycerin produced by hydrolysis of ECH is widely used in alkyd resin, medicine, tobacco, food and explosives industries; chlorohydrin produced by homopolymerization of ECH or dimerization and trimerization with ethylene oxide and propylene oxide Rubber, with heat resistance, oil resistance, ozone resistance, weathering resistance and ot...

AI Technical Summary

Problems solved by technology

Propylene high-temperature chlorination method (also known as chloropropene method) is a classic method for producing epichlorohydrin. The main problems in this process are: serious corrosion of equipment, high energy consumption for production, high chlorine consumption, many by-products, and A large amount of wastewater containing calcium chloride and organic chloride seriously endangers the environment, and the investment in wastewater treatment accounts for about 20% of the total investment

[0006] When titanium-silicon molecular sieves are used as catalysts to oxidize chloropropene, the common problem is that with the prolongation of the reaction time, the catalytic activity of titanium-silicon molecular sieves will show a downward trend, resulting in a decrease in the conversion rate of the oxidant and the selectivity of the target oxidation product.

[0008] However, when the regenerated catalyst is put into operation again, especially after being regenerated in the device, the activity and selectivity of the catalyst fluctuate greatly, and it takes a long time to stabilize; at the same time, it is necessary to combine operations such as increasing the reaction temperature To achieve the smooth operation of the reaction, but this will further accelerate the deactivation of the catalyst and reduce the selectivity of the target oxidation product, affecting the refining and separation of subsequent products, and is also not conducive to safe production

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