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

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...

AI Technical Summary

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.

Images