Benzene tetramethyl acid dianhydride catalyst and preparation method thereof

Abstract

The invention relates to a tetramethyl benzene catalytic oxidation prepared benzene tetramethyl acid dianhydride catalyst, including a spray solution and a carrier, the spray solution comprises by weight of 3-5 parts of partial ammonium vanadate, 11.2-11.4 parts of oxalic acid, 0.2-0.4 part of diammonium hydrogen phosphate, 0.1-0.3 part of sodium phosphate, 0.18-0.2 part of antimony oxide, 1.1-1.3 parts of ammonium molybdate, 0.98-1 part of potassium hydroxide, 0.6-0.8 part of sodium dihydrogen phosphate, 0.18-0.2 part of potassium carbonate, 0.68-0.7 part of potassium dihydrogen phosphate, 1.16-1.18 parts of potassium phosphate and 8.6-8.8 parts of titanium dioxide; the carrier is a 78.5-78.7 parts of ceramic ring; and the catalyst is prepared through the four steps of weighing, apportioning, spraying and roasting. The advantages of the provided catalyst are characterized in that when applying, the catalyst has relatively good activity, high select ability, low heat point reaction temperature, long service life, low energy consumption for certain resources.

Description

technical field [0001] The invention belongs to the technical field of catalytic oxidation, in particular to a catalyst for preparing pyromellitic dianhydride, and also to a preparation method of the catalyst. Background technique [0002] Pyromellitic dianhydride, referred to as homoanhydride or PMDA, is mainly used as a monomer of polyimide film heat-resistant resin, powder coating, matting agent, epoxy resin curing agent and plasticizer. Because PMDA has many excellent properties such as high temperature resistance, impact resistance and cryogenic resistance, the products made of it have been widely used in cutting-edge technology sectors, such as aircraft, aerospace, aviation, electronics industry and other fields. [0003] At present, domestic pyromellitic dianhydride production methods mostly use durene as raw material, vanadium-titanium series yellow catalyst as catalysis, gas phase oxidation method to produce crude product, referred to as crude anhydride, after hydro...

AI Technical Summary

Problems solved by technology

Since the oxidation process of homoanhydride production is a complex heterogeneous catalytic process, it consists of a series of reactions. The demethylation reaction of mesitylene will generate trimethylbenzene, mesitylene, o-xylene, benzene, etc., which will lead to homogeneous The crude anhydride product has low yield, poor quality, heavy color, less crystal particles, and more solid powder; at the same time, the catalyst used has a low weight gain rate and poor selectivity, and the equipment flow and operation process are complicated, and the operating cost is high