Method of preparing adipic acid by directly oxidizing cyclohexane

Abstract

The invention relates to a method for preparing adipic acid by directly oxidizing cyclohexane. The problems of low cyclohexane conversion rate and low adipic acid yield of preparation of adipic acid by directly oxidizing cyclohexane in the prior art are mainly solved. The method for preparing adipic acid by directly oxidizing cyclohexane comprises is characterized in that adipic acid is obtained by oxidizing cyclohexane with an oxygen-containing gas as an oxidant in the presence of a solvent, a free radical catalyst, a metal catalyst and a cocatalyst; the solvent is at least one selected from acetic acid, acetonitrile and ethyl acetate; the free radical catalyst is at least one selected from NHPI (N-hydroxyphthalimide) and NAPI (N-acetoxylphthalimide); the metal catalyst is at least one selected from cobalt and manganese; and the cocatalyst is at least one selected from polyethylene glycol and crown ether. The method well solves the problems, and can be used in the industrial production of adipic acid.

Description

technical field

[0001] The invention relates to a method for directly oxidizing cyclohexane to prepare adipic acid. Background technique

[0002] Adipic acid, also known as fatty acid, is an important organic dibasic acid and an important raw material for the preparation of polyurethane and nylon 66. In the world, adipic acid is used in more than 70% of nylon 66 fields, and in my country, adipic acid is used in polyurethane fields reaching 78%. At present, there are four production methods of adipic acid in the world: phenol method, cyclohexane method, cyclohexene method and butadiene method. Before the 1950s, the production of adipic acid mainly used phenol as the raw material. The production of adipic acid by the phenol method is a relatively classical method. The advantages of this method are high product purity, mature production technology, and no stainless steel materials. However, phenol resources are limited and expensive, and the product cost is high, so it has be...