Hydrofining method and device of caprolactam

Abstract

The invention relates to a caprolactam hydrofining method and a caprolactam hydrofining device. The method comprises the following steps: contacting a caprolactam raw material with a hydrogenation catalyst in a fixed bed reactor and carrying out a hydrogenation reaction; the hydrogenation catalyst is a porous crystalline alloy, and the particle size of the hydrogenation catalyst is 1-8 mm; the hydrogenation catalyst contains nickel, silicon and optional modified metal elements; the modified metal element is selected from one or more of the IB group, the IIB group, the IIIB group, the IVB group, the VIB group, the VIIB group and the VIII group in the periodic table of elements; based on the total weight of the hydrogenation catalyst, the content of the nickel element is 10-70 wt%, the content of the silicon element is 10-80 wt%, and the content of the modified metal element is 0-30 wt%. The caprolactam hydrofining method disclosed by the invention can realize efficient hydrogenation in the fixed bed reactor, and has the advantages of high caprolactam hydrogenation efficiency, continuous and simple process, high caprolactam refined product purity and small influence on subsequent units.

Description

technical field [0001] The present disclosure relates to the field of caprolactam hydrofining, in particular, to a method and device for hydrofining caprolactam. Background technique [0002] Caprolactam, as a monomer of synthetic fibers and engineering plastics, has a large domestic demand and shows a growing trend year by year. At present, there are two main types of industrial production caprolactam process routes: the first type of route uses cyclohexanone as an intermediate product, and then synthesizes cyclohexanone oxime, and cyclohexanone oxime is synthesized into crude caprolactam through Bechmann rearrangement; the second type of route avoids Opened the production link of cyclohexanone, involving other intermediates or other process steps, such as toluene route process, cyclohexane photonitrosation process, etc. However, the physical and chemical properties of unsaturated by-products in crude caprolactam are very similar to those of caprolactam, and their existenc...

AI Technical Summary

Problems solved by technology

Regardless of whether the gap reactor, magnetically stabilized bed reactor or fixed bed reactor is used, the PM value of caprolactam after hydrofining is greatly increased, which can make the PM value usually around 20 000s, but compared with the high-grade caprolactam There is still a large gap between the PM value requirements greater than 30 000s

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