The continuous production method of cyclohexanone oxime

Abstract

The invention discloses a small-scale continuous production method of cyclohexanone oxime, the method firstly prepares and assembles the production system adopted, the production system is connected between the feed system and the reactor, the reactor and the discharge system , and with the heating system, gas supply system, and condensing system, continuous feeding and discharging can be realized. Secondly, titanium-silicon molecular sieves are added to the assembled reactor as a catalyst; then cyclohexanone oxime products are added to the reactor. liquid, turn on the stirring device, turn on the heating system to heat up, turn on the condensation system to start the circulation, to stabilize the production system, heat up the material in the reaction kettle, turn on the raw material tank to start feeding, and open the outlet port while feeding continuously, and wait for the reaction After continuing for 4 to 8 hours, use a membrane separation system to remove the solid particle catalyst in the product liquid and collect the final product. The preparation method of the invention can realize the continuous production from feeding to discharging and the whole-process production of intermediate product collection.

Description

technical field [0001] The invention relates to the technical field of preparation of cyclohexanone oxime, in particular to a continuous production method of cyclohexanone oxime. Background technique [0002] Cyclohexanone oxime is an important intermediate in the production of caprolactam. At present, the production of cyclohexanone oxime mostly adopts the method of direct hydroxylamine salt oximation of cyclohexanone. This kind of process route is complicated, and a large amount of corrosive and polluting raw materials are used. The environment is very harmful. [0003] In order to develop an environmentally friendly synthetic process for cyclohexanone oxime, US4745221A discloses a method for synthesizing cyclohexanone oxime with a mixture of titanium silicon molecular sieve or silicon dioxide molecular sieve as a catalyst, but the selectivity of oxime is low, only 79.45%; US4794198A And US5227525A discloses the technology that uses titanium-silicon molecular sieve as cat...

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Problems solved by technology

[0002] Cyclohexanone oxime is an important intermediate in the production of caprolactam. At present, the production of cyclohexanone oxime mostly adopts the method of direct hydroxylamine salt oximation of cyclohexanone. This kind of process route is complicated, and a large amount of corrosive and polluting raw materials are used. Great harm to the environment

[0003] In order to develop an environmentally friendly synthetic process for cyclohexanone oxime, US4745221A discloses a method for synthesizing cyclohexanone oxime with a mixture of titanium silicon molecular sieve or silicon dioxide molecular sieve as a catalyst, but the selectivity of oxime is low, only 79.45%; US4794198A And US5227525A discloses the technology that uses titanium-silicon molecular sieve as catalyst, tert-butanol-water as solvent to synthesize cyclohexanone oxime in liquid phase, the conversion rate of cyclohexanone can reach 98.3%, and the selectivity of cyclohexanone oxime can be improved. Up to 99.65%; US6462235A discloses a method of using titanium-silicon molecular sieve as a catalyst, under the coexistence of ammonium salt or substituted ammonium salt, using aldehyde or ketone, ammonia and hydrogen peroxide as raw materials for the liquid phase production of oxime. It is very effective for macromolecular cyclic ketones, but it needs to add co-catalyst ammonium salt or substituted ammonium salt in the reaction to obtain high conversion rate and selectivity

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