Method for producing KA oil and adipic acid through oxidizing cyclohexane with air on basis of gas-liquid-solid heterogeneous reaction separation synchronization reactor

Abstract

The invention discloses a method for producing KA oil and adipic acid through oxidizing cyclohexane with air on the basis of a gas-liquid-solid heterogeneous reaction separation synchronization reactor, wherein the water-containing cyclohexane 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 cyclohexane in the reaction, the air is introduced continuously from the bottom of the oxidization area and is in contact with the cyclohexane to carry out the oxidization reaction, meanwhile, a mixed phase of the produced KA oil, adipic acid and water settles and enters the bottom of the constant temperature settlement tower, the cyclohexane in the constant temperature settlement tower is pushed and goes up into the oxidization area to lead to the continuous reaction, the mixed phase continues to settle in the constant temperature settlement tower until the constant temperature settlement tower is fully filled with the mixed phase, then the reaction tower is switched to be communicated with the other constant temperature settlement tower filled with the cyclohexane, the operation is conducted on the constant temperature settlement towers alternatively to continuously produce the KA oil and adipic acid. The method is used to continuously produce the KA oil and the adipic 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 relates to a method for producing KA oil and adipic acid by air oxidation of cyclohexane based on a gas-liquid-solid multiphase reaction separation synchronous reactor, and belongs to the technical field of cyclohexane oxidation chemical industry. Background technique [0002] Air oxidation of cyclohexane yields KA oil (a mixture of cyclohexanol and cyclohexanone) and adipic acid. KA oil is the raw material for the production of caprolactam, which can also be further oxidized to adipic acid. Caprolactam is the monomer for the production of Nylon 6 and adipic acid is the monomer for the production of Nylon 66. Therefore, cyclohexane oxidation is an extremely important chemical production process. The process of cyclohexane oxidation to produce KA oil and adipic acid is as follows: [0003] [0004] Industrially, the method for producing KA oil by oxidation of cyclohexane is the non-catalyzed air oxidation method of Stamicka, the Neth...

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Problems solved by technology

However, the current cyclohexane oxidation industrial technology and other disclosed technologies still have the following problems: one is that during the entire reaction of cyclohexane air oxidation to prepare KA oil and adipic acid, the reaction raw material cyclohexane, air, and oxidation intermediates Peroxide and oxidation products KA oil and adipic acid coexist in the reaction zone, and these oxidation products will be further oxidized and decarboxylated to form other complex oxidation products; the second is that the oxidation product adipic acid is a solid product insoluble in cyclohexane. During the reaction process, it is easy to crystallize at the bottom of the oxidation reactor and in the flow pipeline, which will block the pipeline and affect the fluidity of the liquid in the production device, making continuous production impossible; the third is that the cyclohexane distillation separation tower separates a large amount of unreacted raw material rings The process of hexane needs to consume a lot of energy; the fourth is that the oxidation product adipic acid stays in the reaction system for a long time, and under the conditions of high temperature and high pressure, some products are further decarboxylated to form by-products, which increases the difficulty of product separation

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