Multistage rearrangement system and method for preparation of caprolactam from cyclohexanone oxime

A technology for cyclohexanone oxime and caprolactam, which is applied in the field of preparing caprolactam from cyclohexanone oxime by multi-stage rearrangement, can solve the problems of difficult temperature control, low production capacity, incomplete reaction and the like, and achieves improved controllability and safety, Strictly control the residence time and improve the effect of reaction selectivity

Active Publication Date: 2012-10-10
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

One of the characteristics of the Beckmann rearrangement reaction is the large heat release and the temperature is not easy to control
Conventional reactors use external circulation to extract heat, and its circulation ratio can be as high as 245, which leads to low equipment production capacity, high operating costs, and poor safety and reliability of the reactor and reaction process
Another feature of the Beckmann rearrangement reaction is that there is a critical value for the acid oxime ratio (the molar ratio of concentrated sulfuric acid or oleum to cyclohexanone oxime), which will easily lead to incomplete Beckmann rearrangement reactions and side effects if the ratio is lower than the critical value. reaction

Method used

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  • Multistage rearrangement system and method for preparation of caprolactam from cyclohexanone oxime
  • Multistage rearrangement system and method for preparation of caprolactam from cyclohexanone oxime
  • Multistage rearrangement system and method for preparation of caprolactam from cyclohexanone oxime

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Experimental program
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Effect test

Embodiment 1

[0027] A method for preparing caprolactam from cyclohexanone oxime by multi-stage rearrangement is carried out according to the following steps:

[0028] a. Dissolving cyclohexanone oxime in n-octane solution to form a solution with a cyclohexanone oxime mass fraction of 10%, and adding it to the cyclohexanone oxime liquid addition tank;

[0029] B, with SO Content is 20wt.% fuming sulfuric acid as dispersed phase, cyclohexanone oxime solution is as continuous phase, injects first micro-mixer through oleum filling tank and cyclohexanone oxime filling tank respectively, disperses The phase flow rate is 1.1mL / min, the flow rate of the continuous phase injected into the first micro-mixer is 20mL / min, and the Beckmann rearrangement reaction is caused by rapid mixing, and the temperature of the reaction system is 90°C;

[0030] c. Pass the mixture after the Beckmann rearrangement reaction into the second micro-mixer, mix with the cyclohexanone oxime solution added in the second mic...

Embodiment 2

[0034] A method for preparing caprolactam from cyclohexanone oxime by multi-stage rearrangement is carried out according to the following steps:

[0035] a. Dissolving cyclohexanone oxime in n-octane solution to form a solution with a mass fraction of cyclohexanone oxime of 1%, and adding it to the cyclohexanone oxime liquid addition tank;

[0036] b. Put SO 3 Content is the oleum of 20wt.% as dispersed phase, and cyclohexanone oxime solution is used as continuous phase, injects the first micro-mixer through oleum filling tank and cyclohexanone oxime filling tank respectively, and dispersed phase flow rate is 2.4 mL / min, the flow rate of the continuous phase injected into the first micro-mixer is 20mL / min, rapid mixing and triggering Beckmann rearrangement reaction, the temperature of the reaction system is 90°C;

[0037] c. Pass the mixture after the Beckmann rearrangement reaction into the second micro-mixer, mix with the cyclohexanone oxime solution added in the second mic...

Embodiment 3

[0041] A method for preparing caprolactam from cyclohexanone oxime by multi-stage rearrangement is carried out according to the following steps:

[0042] a, dissolving cyclohexanone oxime in n-octane solution, making cyclohexanone oxime mass fraction is 18% solution, joins cyclohexanone oxime filling tank;

[0043] b. Put SO 3 The oleum with a content of 20wt.% is used as the dispersed phase, and the cyclohexanone oxime solution is used as the continuous phase, which is injected into the first micro-mixer through the oleum filling tank and the cyclohexanone oxime filling tank respectively, and the flow rate of the dispersed phase is 2.0 mL / min, the flow rate of the continuous phase injected into the first micro-mixer is 20mL / min, rapid mixing and triggering Beckmann rearrangement reaction, the temperature of the reaction system is 70°C;

[0044] c. Pass the mixture after the Beckmann rearrangement reaction into the second micro-mixer, mix with the cyclohexanone oxime solution...

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Abstract

The invention discloses a multistage rearrangement system and a method for preparation of caprolactam from cyclohexanone oxime, and belongs to the technical field of organic compound synthesis. The method employs a plurality of micro mixers in series to realize Beckman rearrangement process through multistage. In a first micro mixer, 6-30 wt% of oleum is used as a disperse phase, and cyclohexanone oxime is dissolved in an inertia solvent to be used as a continuous phase; the disperse phase and the continuous phase are mixed to initiate a rearrangement reaction, and continue to react with replenished cyclohexanone oxime in micro mixers from No.2 to No.4; and two adjacent micro mixers are in series and connected by pipelines. Reaction materials flow out from a last micro mixer, and are slaked for 40-120s thorough pipelines, then are sent for hydrolysis reaction to separate the inertia solvent and the caprolactam. Utilizing the method, process security can be further enhanced; cycle operation can be avoided; and output of a by-product ammonium sulfate can be reduced substantially.

Description

technical field [0001] The invention belongs to the technical field of organic compound synthesis, in particular to a system and method for preparing caprolactam from cyclohexanone oxime by multi-stage rearrangement. Background technique [0002] 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. [0003] The conversion of cyclohexanone oxime to caprolactam through liquid-phase Beckmann rearrangement reaction is a technology commonly used in industry at present, and the catalyst used is usually concentrated sulfuric acid or oleum. One of the characteristics of the Beckmann rearrangement reaction is that the heat release is large and the temperature is not e...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D201/04C07D223/10
Inventor 张吉松王凯吕阳成骆广生
Owner TSINGHUA UNIV
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