Preparation method of caprolactam and N-substituted caprolactam

Abstract

The invention provides a preparation method of caprolactam and N-substituted caprolactam, comprising the following steps: adding a catalyst, namely filling a fixing bed with 150.0-200.0g of granular SO4<2-> / MxOy type solid superacid catalyst with phi=4.0-6.0 heating, namely heating to raise the temperature to 180.0-320.0 DEG C; and introducing nitrogen, namely introducing nitrogen to the fixing bed at the air speed of 50.0-70.0cm<3> / min, so as to enable the catalyst to be in a state of being protected by nitrogen all the time. According to the preparation method, 6-caprolactone and ammonia (amine) are taken as raw materials, the raw materials are gasified at normal pressure and under nitrogen protection and then react by the fixing bed filled with the solid superacid catalyst, the productundergoes condensation and collection and is treated by a dehydration desolvent to obtain high-purity caprolactam and N-substituted caprolactam, the yield reaches 95% or above, the catalysis process is simple, the product yield and purity are high, the cost is low, continuous production is realized, and industrial production is benefited.

Description

technical field [0001] The invention relates to the technical field of preparation of caprolactam and N-substituted caprolactam, in particular to a preparation method of caprolactam and N-substituted caprolactam. Background technique [0002] Caprolactam and N-substituted caprolactam are important fine chemicals and pharmaceutical intermediates. Among them, caprolactam is one of the important organic chemical raw materials. Its main purpose is to generate polyamide chips (usually called nylon-6 chips, or nylon-6 chips) through polymerization, which can be further processed into nylon fibers, engineering plastics, and plastic films; N- Methylcaprolactam and N-ethylcaprolactam are important intermediates and solvents in organic synthesis; N-hydroxyethylcaprolactam is the precursor for the synthesis of poly-N-vinylcaprolactam, also known as PNVCL, which is a promising drug release agent At the same time, it plays an important role in artificial muscles, drug controlled release...

AI Technical Summary

Problems solved by technology

[0003] At present, the methods for producing caprolactam at home and abroad are basically the oxime method: firstly, high-purity cyclohexanone and hydroxylamine sulfate are condensed at 80-110°C to generate cyclohexanone oxime, and the separated cyclohexanone oxime is converted into fuming sulfuric acid As a catalyst, it is transformed into crude caprolactam by Beckmann rearrangement at 80-110°C. The crude caprolactam is extracted, distilled, crystallized and other processes to obtain high-purity caprolactam. This method requires oleum as a catalyst, which will cause serious corrosion to the equipment , the operation requirements are very strict, and the post-treatment process will produce a large amount of waste water, which will pollute the environment. The chemical equation is:

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