Total mixed flow-plug flow combined cyclohexanone ammoximation process and device

Abstract

The invention discloses a complete mixed flow-plug flow combined cyclohexanone ammoximation process and device, cyclohexanone, ammonia and hydrogen peroxide are used as raw materials, a titanium silicon catalyst is adopted, an organic solvent or water is used as a solvent, and the complete mixed flow-plug flow combined cyclohexanone ammoximation process comprises the following three steps: S1, mixing oximation raw materials with refluxed post-oximation thick slurry in a loop reactor, and converting into a pre-oximation product in a complete mixed flow manner; s2, performing oximation on the pre-oximation product in a tubular reactor in a plug flow manner, and converting the pre-oximation product into a post-oximation product; and S3, carrying out two-stage separation of sedimentation and membrane filtration on the post-oximation product, extracting a clear liquid for purifying cyclohexanone-oxime, and pumping the remaining thick slurry back to the pre-oximation. By optimizing the flow field, the oximation process is improved, the reaction time is shortened, and the yield of cyclohexanone-oxime is increased.

Description

technical field [0001] The invention relates to the field of chemical production, in particular to the field of production of a nylon 6 intermediate cyclohexanone oxime. Background technique [0002] Caprolactam is a nylon 6 polymerized monomer, and cyclohexanone oxime is an intermediate in the synthesis of caprolactam. [0003] At present, the mainstream route of producing cyclohexanone oxime is to use titanium-silicon molecular sieve catalyst to directly oximation with cyclohexanone, hydrogen peroxide and ammonia as raw materials: [0004] [0005] The reaction temperature is 60-95° C., the pressure is 0.2-0.6MPa, the molar ratio of ammonia and cyclohexanone is 1.2-3.0, and the molar ratio of hydrogen peroxide and cyclohexanone is 1.02-1.12. [0006] An organic solvent, such as tert-butanol, can be added to the reactant; or water can be used as a solvent without adding an organic solvent. The oximation process without adding organic solvent saves the distillation proc...

AI Technical Summary

Problems solved by technology

In the early stage of the circulation, the reaction rate is fast and the heat release is strong. A high circulation ratio is necessary for temperature control. In the later stage of the circulation, the reaction rate is slow and the heat release is weak. The high circulation ratio does more harm than good

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