A heterogeneous catalyst and its preparation method, and a method for preparing 3,5-dimethylphenol using the catalyst

Abstract

The present invention relates to a heterogeneous catalyst and a preparation method thereof, and also relates to a method for preparing 3,5-dimethylphenol by aromatization of isophorone (IP) using the heterogeneous catalyst. The heterogeneous catalyst comprises an active component, a carrier, and optional additives, the active component comprising Ni, NiO, Cr 2 o 3 and Co 3 o 4 . Activated heterogeneous catalyst for isophorone aromatization with simultaneous aromatization activity and methane CO 2 Reforming reaction activity, the heterogeneous catalyst has good activity, high selectivity, and good stability. When used in conjunction with a homogeneous catalyst, it can effectively reduce the amount of homogeneous catalyst used, and at the same time reduce the amount of carbon deposition and prolong the use of the catalyst time.

Description

technical field [0001] The invention belongs to the field of catalysts, in particular to a catalyst for preparing 3,5-dimethylphenol from isophorone and a preparation method thereof, and also to a method for preparing 3,5-dimethylphenol. Background technique [0002] 3,5-Dimethylphenol is an important organic synthesis intermediate and fine chemical raw material, widely used in the production of vitamins, disinfectants, rubber, dyes, paints, etc. The main domestic use is to chlorinate 3,5-dimethylphenol to produce 4-chloro-3,5-dimethylphenol (PCMX), which is a highly effective disinfectant and preservative used in soaps and Detergents such as hand sanitizer. Under the catalysis of noble metal catalyst, 3,5-dimethylphenol can synthesize high-grade dye intermediate 3,5-dimethylaniline by introducing hydrogen and ammonia gas; Kylation reaction can produce 2,3,5-trimethylphenol, which is used as a raw material for the preparation of medicines. The reaction of dimethyl disulfi...

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Problems solved by technology

At present, the main problems of the first three methods are: low product selectivity and low by-products; strong acid and / or strong alkali are used in the process, the equipment is severely corroded, the process is complicated, and it is difficult to obtain a product with higher purity

[0008] (1) The catalyst mostly uses a single type of catalyst, and the single-phase catalyst has a decline in catalytic effect due to its own limitations;

[0009] (2) Carbon deposition is serious during the reaction process, and the carbon powder generated during the reaction process will block the reactor after a long period of accumulation, causing the passive shutdown of the entire reaction system;

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