Method for producing substituted benzyl alcohol, substituted benzaldehyde and substituted benzyl acid through oxidizing substituted methylbenzene with air based on gas-liquid-solid heterogeneous reaction separation synchronization reactor

Abstract

The invention discloses a method for producing substituted benzyl alcohol, substituted benzaldehyde and substituted benzyl acid through oxidizing substituted methylbenzene with air on the basis of a gas-liquid-solid heterogeneous reaction separation synchronization reactor, wherein the water-containing substituted methylbenzene is added into the reactor, the reactor comprises a reaction tower and at least two constant temperature settlement towers communicated with the bottom of the reaction tower, and the reaction tower is internally provided with a gas phase area, an oxidization area and a gas outlet; the oxidization area and the constant temperature settlement towers are filled with the substituted methylbenzene in the reaction, the air is introduced continuously from the bottom of the oxidization area and is in contact with the substituted methylbenzene to carry out the oxidization reaction, meanwhile, a mixed phase of the produced substituted benzyl alcohol, substituted benzaldehyde and substituted benzyl acid settles and enters the bottom of the constant temperature settlement tower, the substituted methylbenzene in the constant temperature settlement tower is pushed into the oxidization area to lead to the continuous reaction, the reaction tower is switched to be communicated with the other constant temperature settlement tower filled with the substituted methylbenzene when the constant temperature settlement tower is fully filled with the mixed phase, the operation is conducted on the constant temperature settlement towers alternatively to continuously produce the substituted benzyl alcohol, substituted benzaldehyde and substituted benzyl acid. The method is used to continuously produce the substituted benzyl alcohol, substituted benzaldehyde and substituted benzyl acid with high percent of conversion and high selectivity, the production efficiency is improved, and the production cost is lowered.

Description

technical field [0001] The invention discloses a method for producing substituted benzyl alcohol, aldehyde and acid by using air oxidation to replace toluene based on a gas-liquid-solid multiphase reaction separation synchronous reactor, and belongs to the field of substituted toluene oxidation. Background technique [0002] Oxidation of substituted toluene can give the corresponding oxygenates substituted benzyl alcohol, substituted benzaldehyde and substituted benzoic acid. These oxygen-containing compounds are widely used in chemical industry, materials, medicine and other fields. In the oxidation reaction of substituted toluene, substituted benzyl alcohol and substituted benzaldehyde are intermediate oxidation products, which are easily further oxidized to substituted benzoic acid. In industry, the air liquid phase oxidation reaction of substituted toluene requires high temperature and high pressure conditions, and needs cobalt acetate or manganese acetate to catalyze, ...

AI Technical Summary

Problems solved by technology

But, still there is following problem in this scheme: the one, during the whole reaction period of corresponding substituted benzyl alcohol and substituted benzaldehyde prepared in substituted toluene air oxidation, reaction raw material substituted toluene, air and reaction intermediate oxidation product substituted benzyl alcohol and substituted benzaldehyde coexist In the reaction zone, these oxidation products will be further oxidized into substituted benzoic acid; the second is that the oxidation product benzoic acid is a solid product insoluble in toluene, which is prone to crystallization and blockage at the bottom of the oxidation reactor and in the flow line during the continuous reaction process The pipeline affects the fluidity of the liquid in the production device and cannot be continuously produced; the third is that the process of separating toluene in the toluene distillation and separation tower consumes a lot of energy; the fourth is that the oxidation product replaces benzoic acid and stays in the reaction system for a long time. Under high pressure conditions, some products are further decarboxylated to form by-products, which increases the difficulty of product separation

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