Method for producing caprolactam by taking high-purity benzene as raw material

Abstract

The invention provides a method for producing caprolactam by taking high-purity benzene as a raw material, and the method comprises the following steps of: A. preparing cyclohexene from the raw material benzene through hydrogenation; B. separating and purifying cyclohexene; C. carrying out hydration on the cyclohexene for preparing cyclohexanol; D. separating and purifying cyclohexanol; E. carrying out dehydrogenation on cyclohexanol for preparaing cyclohexanone; F. refining cyclohexanone; G. carrying out oximation on cyclohexanone so as to prepare cyclohexanone-oxime; H. refining cyclohexanone-oxime; I. carrying out rearrangement on refined cyclohexanone-oxime so as to prepare caprolactam; and J. refining caprolactam, wherein the high-purity benzene is adopted as a raw material, so that the purity of benzene is more than 99.95%, the sulphur content is less than 5ppm, and the methylbenzene is not more than 100ppm. The method has the beneficial effects that the high-purity benzene is adopted as a raw material, so that the impurity is less, and the product quality is high; the raw material is high in comprehensive utilization rate and low in hydrogen consumption; and the mass of the raw material and intermediate products generated in all the steps of reaction can be strictly controlled, so that the direct commercial value of the intermediate products is fully exerted, and the optimal quality of the product caprolactam can be reached.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis and relates to a method for producing caprolactam. Background technique [0002] Caprolactam (CPL) is an important monomer for the production of nylon 6 and nylon-6 engineering plastics, which has excellent thermal stability, processability, mechanical properties and chemical resistance. Widely used in automobiles, ships, medical products, daily necessities, electronics and electronic components and other fields. [0003] The industrial production methods of caprolactam mainly include phenol method, toluene method and benzene method. Due to the high price of toluene and phenol, they are not easy to obtain. At present, the benzene method occupies the mainstream, accounting for about 80% of the world's total capacity. The traditional benzene method to produce caprolactam includes hydrogenation of benzene to cyclohexane, air oxidation and decomposition of cyclohexane to cyclohexanone, pre...

AI Technical Summary

Problems solved by technology

However, no specific measures have been proposed for the quality control of raw material impurity requirements, intermediate products and final products in each step in the synthesis method of cyclohexanone.

Moreover, the method only involves the step of producing cyclohexanone from coking benzene, and does not explain whether the quality index of this cyclohexanone can be used to produce caprolactam, and does not involve the production steps of caprolactam

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