A process for preparing 2,3,5-trimethyl-p-benzoquinone by catalytic oxidation

Abstract

The invention relates to a process for preparing 2,3,5-trimethyl p-benzoquinone by means of catalytic oxidation, belonging to the technical field of preparation of the 2,3,5-trimethyl p-benzoquinone.A new process for preparing the 2,3,5-trimethyl-p-benzoquinone is formed by combining a supergravity reactor with the conventional stirred tank reactor. The process uses pure-oxygen or oxygen-rich gasas an oxidant and takes an aqueous solution of a metal halide as a catalyst, a reactant, i.e., 2,3,6-trimethylphenol is dissolved in an organic solvent, and the whole reaction process is carried outin the supergravity reactor and the stirred tank reactor. The supergravity reactor has an ability to enhance liquid-liquid mixing and gas-liquid mass transfer, so that the process can enhance the catalytic effect of the catalyst, increase the reaction rate and shorten the production time; in addition, due to the introduction of the supergravity reactor, the utilization rate of oxygen is increased,an oxidation reaction of the 2,3,6-trimethylphenol is promoted, and the yield of the product per unit time is increased.

Description

technical field [0001] The invention relates to a method for preparing 2,3,5-trimethyl-p-benzoquinone, belonging to the technical field of 2,3,5-trimethyl-p-benzoquinone preparation. Background technique [0002] 2,3,5-Trimethyl-p-benzoquinone is an important intermediate in the synthesis of vitamin E. At present, there are many methods for preparing 2,3,5-trimethyl-p-benzoquinone by oxidation of 2,3,6-trimethylphenol. The traditional method is to sulfonate 2,3,6-trimethylphenol with sulfuric acid, and then oxidize it with manganese ore powder as an oxidant. This traditional preparation method has a low yield, and produces a large amount of industrial wastewater and waste residue, causing environmental pollution, and is gradually being eliminated. At present, the method of preparing 2,3,5-trimethyl-p-benzoquinone by catalyzing the oxidation of 2,3,6-trimethylphenol with green oxidants such as oxygen or hydrogen peroxide has received extensive attention, and the resulting y...

AI Technical Summary

Problems solved by technology

Although solid-state catalysts have shown unique advantages in product separation, quality control, and catalyst recovery and recycling, most of this direction is still in the laboratory exploration stage, immature, and there are not many practical industrial applications

[0005] Through relevant technical research in this field, it is found that the current methods for preparing 2,3,5-trimethyl-p-benzoquinone by catalytic oxidation of 2,3,6-trimethylphenol have the following common points: firstly, most of them are Gas-liquid or gas-liquid-liquid reaction process, so it has high requirements for liquid-liquid mixing and gas-liquid mass transfer; the second point is that the whole reaction process is carried out in a traditional stirred tank reactor, and the liquid-liquid is promoted by stirring. liquid mixing and oxygen absorption; the third point is that due to the slow oxidation reaction, most of the oxygen leaves the system without sufficient reaction, and the oxygen utilization rate is not high; the last point is that although a higher yield can be achieved in the end, the reaction time is generally Longer, less productive

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