Method for continuously preparing hexanolactam by using cyclohexanone-oxime Beckmann rearrangement reaction

A rearrangement reaction, cyclohexanone oxime technology, applied in the preparation of lactam, chemical instruments and methods, organic chemistry, etc., can solve the problems of complicated device design and operation control, uneasy stability of reaction results, and a large amount of inert solvents , to achieve the effect of easy device design, stable operation and high yield

Inactive Publication Date: 2010-10-06
XIANGTAN UNIV
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Problems solved by technology

However, due to the large amount of heat released by the re-emission of cyclohexanone oxime, this method that relies entirely on vaporization to absorb heat requires a large amount of inert solvent and generates a large amount of gas in an instant, which complicates the device design and operation control, and makes the reaction result difficult to be stable.
Therefore, this method is very difficult to implement industrially, and in fact, this method of rearrangement of solvent vaporization and heat removal is generally not adopted.

Method used

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  • Method for continuously preparing hexanolactam by using cyclohexanone-oxime Beckmann rearrangement reaction
  • Method for continuously preparing hexanolactam by using cyclohexanone-oxime Beckmann rearrangement reaction

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Embodiment

[0026] The present invention can be achieved through a figure 1 The shown circulation reaction system consisting of circulation pump A, cooler B, mixing reactor C and aging reactor D is implemented.

[0027]The rearrangement reaction solution 1 with a mass content of caprolactam of 50.2% and a flow rate of 20.2 kg / h from the aging reactor D is mixed with oleum with a flow rate of 0.68 kg / h and a mass content of sulfur trioxide of 21%. Finally, it is sent to the temperature controller through the circulation pump A, and the temperature is controlled at 80°C, and then mixed with the cyclohexanone oxime-cyclohexane solution with a flow rate of 1.70kg / h and a cyclohexanone oxime mass content of 39.8%. Reactor C mixes and reacts and enters aging reactor D under normal pressure, where cyclohexane 4 flows out from the gas phase pipeline and is condensed and recovered. After the liquid phase is aged at 100°C for 30 minutes, a part of The rate flows out of the reaction system as the r...

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Abstract

The invention discloses a method for continuously preparing hexanolactam by using a cyclohexanone-oxime Beckmann rearrangement reaction. A circular reaction system consists of a recycle pump, a cooler, a mixing reactor and a curing reactor, and the circular reaction system is characterized in that heat instantly released from the rearrangement reaction is dissipated by combining heat storage of materials with heat absorption in solvent vaporization. The combination of the heat storage of the materials with the heat absorption in the thermal inertia solvent vaporization can control a micro-reaction temperature, and meanwhile, the heat absorption in the thermal inertia solvent vaporization can prevent over-high temperature of the partial reaction, so a reaction product with high yield and high quality can be obtained, the use amount of fuming sulphuric acid is small, the energy consumption is low and the operation is stable.

Description

technical field [0001] The invention relates to a method for continuously preparing caprolactam by the Beckmann rearrangement reaction of cyclohexanone oxime. Background technique [0002] Caprolactam, scientific name ε-caprolactam, molecular formula C 6 h 11 NO, the molecular weight is 113.16, it is a white crystal at room temperature, and the melting point is 69.3°C. As a monomer of polyamide 6, it is an important petrochemical product with high quality requirements, and is widely used in the manufacture of nylon and engineering plastics. [0003] There are many preparation methods for caprolactam, and the preparation of caprolactam by Beckmann rearrangement of cyclohexanone oxime is one of the methods with the most industrial significance at present. The Beckmann rearrangement reaction process of cyclohexanone oxime under the action of oleum is a strongly exothermic reaction, that is, the heat of reaction is >254kJ / mol cyclohexanone oxime, and cyclohexanone oxime ca...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D223/10C07D201/06
Inventor 罗和安吴剑袁霞
Owner XIANGTAN UNIV
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