Heterogeneous rearrangement method for preparing caprolactam from cyclohexanone oxime

A technology of cyclohexanone oxime and caprolactam, which is applied to the preparation of lactam, chemical instruments and methods, organic chemistry and other directions, can solve the problems of unsatisfactory solution, unstable process, low heat transfer efficiency, etc., and achieves enhanced reaction process control, The effect of improving the selectivity of the reaction and reducing the temperature rise of the reaction

Inactive Publication Date: 2020-01-14
TSINGHUA UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The above heat exchange technology is mainly realized by vaporization during the reaction process, but the vaporization method has problems such as process instability and difficult operation, which are not conducive to industrial scale-up
Patent document 3CN109503484 uses a high boiling point inert solvent for the reaction, but simply using an inert solvent to transfer heat still has problems such as low heat transfer efficiency and many reaction impurities
Therefore, the existing process still cannot meet the needs of solving the existing problems

Method used

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  • Heterogeneous rearrangement method for preparing caprolactam from cyclohexanone oxime

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Embodiment 1

[0040] Experiment according to the method of the present invention, the n-decane solution (2) of the cyclohexanone oxime of 12.5kg / h, wherein cyclohexanone oxime massfraction 8%, with the oleum (7) of the 10% concentration of 1kg / h ) and 2kg / h of the mixed solution of the circulating acid phase (4) are mixed in the microreactor (II), and the inlet temperature is 80°C, and enters the phase separator for phase separation, and the phase separator temperature is 100°C. The reaction acid oxime ratio (that is, the molar ratio of oleum added to cyclohexanone oxime) is 1.2, the circulation ratio is 1, and the total residence time of the reaction is 30 min. Reaction conversion >99.9%, selectivity >99.5%.

Embodiment 2

[0042] Experiment according to the method of the present invention, the D80 solution (2) of the cyclohexanone oxime of 20kg / h, wherein cyclohexanone oxime mass fraction 5%, with the oleum (7) of the 20% concentration of 1kg / h and 1kg The mixed solution of circulating acid phase (4) per hour is mixed in the stirred reactor (II), the inlet temperature is 60°C, and enters the phase separator for phase separation, and the temperature of the phase separator is 100°C. The reaction acid oxime ratio (that is, the molar ratio of adding fuming sulfuric acid to cyclohexanone oxime) is 1.2, the circulation ratio is 0.5, and the total residence time of the reaction is 20 minutes. Reaction conversion >99.9%, selectivity >99.6%.

Embodiment 3

[0044]Experiment according to the method of the present invention, the n-octane solution (2) of the cyclohexanone oxime of 12.5kg / h, wherein cyclohexanone oxime massfraction 8%, with the oleum of 20% concentration of 1.2kg / h ( 7) mixed with 10kg / h of the circulating acid phase (4) in the microreactor (II), the inlet temperature is 80°C, and enters the phase separator for phase separation, the temperature of the phase separator is 100°C. The reaction acid oxime ratio (that is, the molar ratio of oleum added to cyclohexanone oxime) is 1.4, the circulation ratio is 5, and the total residence time of the reaction is 30 minutes. Reaction conversion >99.9%, selectivity >99.8%.

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Abstract

The invention belongs to the technical field of chemical reaction engineering and particularly relates to a heterogeneous rearrangement method for preparing caprolactam from cyclohexanone oxime. The method comprises the steps: dissolving the cyclohexanone oxime into a recycled inert solvent to form an inert solvent solution of the cyclohexanone oxime, subjecting the inert solvent solution of the cyclohexanone oxime to a reaction with a cyclic acid phase containing caprolactam and fuming sulfuric acid in a rearrangement reactor, then, dividing the reaction solution into two phases, i.e., an inert solvent phase and an acid phase by a phase splitter, mixing the acid phase with the fuming sulfuric acid prior to cycling one part of the acid phase to the rearrangement reactor, then, enabling themixture to enter the rearrangement reactor, and discharging the other part of the acid phase at a corresponding inflow velocity of inlet raw materials; and cycling the inert solvent phase to preparethe inert solvent solution of the cyclohexanone oxime. According to the method disclosed by the invention, the reaction rate can be greatly increased, the selectivity can be greatly improved, and theenergy consumption of a process can be lowered.

Description

technical field [0001] The invention belongs to the technical field of chemical reaction engineering, in particular to a heterogeneous rearrangement method for preparing caprolactam from cyclohexanone oxime. Background technique [0002] Caprolactam, scientific name ε-caprolactam, is an important organic chemical raw material, mainly used in the production of nylon 6 fiber (nylon 6) and nylon 6 engineering plastics. Among them: nylon 6 fiber is widely used in wool spinning, knitting, weaving, carpet and other industries, and nylon 6 engineering plastics is widely used in electronics, automobiles, packaging films and other industries. In 2018, the consumption of caprolactam in my country has reached 3.01 million tons, the domestic output is 2.84 million tons, and the self-sufficiency rate is 94%. The domestic production capacity is 3.79 million tons, and the operating rate is only 74.9%. The competition among enterprises is fierce, and there is an urgent need to reduce produc...

Claims

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Application Information

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IPC IPC(8): C07D223/10C07D201/04
CPCC07D201/04C07D223/10
Inventor 骆广生杜晨灿张吉松
Owner TSINGHUA UNIV
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