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Process for preparation of caprolactam

A technology of cyclohexanone oxime and ionic liquid, which is applied in the field of preparation of caprolactam, can solve the problems of reaction rate control, difficulty in obtaining heat from the system, separation of difficult reaction products from the catalytic system, expensive ionic liquid, etc., and achieve high selectivity liquid phase Effects of Beckmann rearrangement reaction, energy consumption reduction and production cost reduction

Inactive Publication Date: 2005-01-19
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in practice, the use of ionic liquids for Beckmann rearrangement has the following problems: (1) the Beckmann rearrangement reaction of cyclohexanone oxime is a strong exothermic reaction, and it is very difficult to control the reaction rate and obtain heat from the system; (2) if all Using ionic liquid as the catalytic phase will greatly increase the production cost, because the price of ionic liquid is very expensive; (3) the homogeneous reaction system is difficult to realize the separation of the reaction product and the catalytic system

Method used

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  • Process for preparation of caprolactam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] This example illustrates that the method provided by the present invention can be implemented in a hydrophilic ionic liquid under different catalyst to cyclohexanone oxime dosage ratios.

[0036] In a 100ml round bottom flask, add 2.0ml of hydrophilic ionic liquid [bmim][BF 4 ], 5.00ml toluene (product of Beijing Chemical Reagent Company, analytically pure) and 0.50ml POCl 3 (product of Beijing Chemical Reagent Company, analytically pure), the temperature of the oil bath is controlled at 80 ° C, and under magnetic stirring, cyclohexanone oxime-toluene solutions with different volumes and a concentration of 2.00 mol / L are added dropwise (cyclohexanone oxime is produced by Yueyang Yingshan Provided by the caprolactam factory, content > 99.5%), after 30 minutes of reaction, static phase separation, thereby completing the Beckmann rearrangement reaction.

[0037] Add 5.00ml of 10% ammonia water to the ionic liquid phase to quench the reaction, then extract twice with 5.00m...

Embodiment 2

[0039] This example illustrates that the method provided by the present invention can be implemented in hydrophilic ionic liquids with different catalyst dosages.

[0040] In a 100ml round bottom flask, add 2.0ml of hydrophilic ionic liquid [bmim][BF 4 ], 5.00ml toluene and different volumes of POCl 3 , the temperature of the oil bath is controlled at 80°C, and 10.00 ml of cyclohexanone oxime-toluene solution with a concentration of 1.00 mol / L is added dropwise under magnetic stirring, and the phase is separated after 30 minutes of static reaction, thereby completing the Beckmann rearrangement reaction.

[0041] The results analyzed according to the method of Example 1 are listed in Table 2.

[0042] Table 1.

[0043] Cyclohexanone oxime conversion with cyclohexanone oxime Selectivity, % Catalytic conversion number

[0044] Amount, ml Yield, % Cyclohexanone Caprolactam Others (TON)

[0045]5.00 99.77 0.00 98.59 1.41 1.83

[0046] 7.50 94.06 5.79 91.73 2.48 2.58

[0047] ...

Embodiment 3

[0057] This example illustrates that the method provided by the present invention can be implemented in hydrophilic ionic liquids at different dosages of ionic liquids.

[0058] In a 100ml round bottom flask, add different volumes of hydrophilic ionic liquid [bmim][BF 4 ], 5.00ml toluene and 0.50ml POCl 3 , the temperature of the oil bath is controlled at 80°C, under magnetic stirring, different volumes of cyclohexanone oxime-toluene solutions with a concentration of 2.00 mol / L are added dropwise, and after 30 minutes of reaction, the phases are separated at rest, thereby completing the Beckmann rearrangement reaction.

[0059] The results analyzed according to the method of Example 1 are listed in Table 3.

[0060] table 3.

[0061] Ionic Liquid Cyclohexanone Oxime Oxime Conversion Selectivity, % Catalytic Conversion Number

[0062] ml ml % Cyclohexanone Caprolactam Other (TON)

[0063] 2.0 7.50 91.52 5.43 91.58 2.99 2.51

[0064] 3.0 7.50 58.51 6.13 85.27 8.60 1.61

[...

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Abstract

The invention discloses a process for preparation of caprolactam from cyclic ketones through liquid phase rearrangement reaction in ionic liquid and at the presence of phosphorus-containing compounds as the catalyst, wherein the ionic liquid, organic solvent non-dissolving to the ionic liquids and acidic phosphorus-containing compound catalyst are mixed under stirring condition, dissolving the catalyst into the ionic liquid phase, heating the obtained two phase catalytic system to a rearrangement reaction temperature, charging the cyclic ketones or solution into the catalytic system for reaction, then subjecting to stewing and phase-splitting.

Description

technical field [0001] The invention relates to a method for preparing caprolactam through Beckmann rearrangement reaction of cyclohexanone oxime. More specifically, it relates to a method for preparing caprolactam through a liquid-phase Beckmann rearrangement reaction of cyclohexanone oxime in an ionic liquid, using a phosphorus-containing compound as a catalyst. technical background [0002] Caprolactam is an important organic chemical raw material with wide application. About 90% of caprolactam in the world is prepared from cyclohexanone oxime through Beckmann rearrangement reaction. The traditional Beckmann rearrangement reaction process is: use fuming sulfuric acid to make cyclohexanone oxime form caprolactam salt of sulfuric acid, and in order to obtain a high yield of caprolactam, it is necessary to add excess sulfuric acid, and then neutralize the mixture with ammonia water to obtain ammonium sulfate and caprolactam . In this way 0.5 moles of ammonium sulfate will...

Claims

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Application Information

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IPC IPC(8): C07D201/06
Inventor 张伟吴巍张树忠胡合新闵恩泽
Owner CHINA PETROLEUM & CHEM CORP
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