Process for extracting and separating caprolactam from amide oil

Abstract

The invention provides a process for extracting and separating caprolactam from amide oil which comprises, using cyclohexane or the mixed solvent of cyclohexane and benzene to pre-extract amide oil and remove part of the impurity, then using benzene or the mixed solvent of cyclohexane and benzene to extract the dense phase obtained from the pre-abstraction, finally back washing the light phase with water to obtain the water solution of caprolactam.

Description

technical field [0001] The invention relates to a method for extracting and purifying caprolactam from amide oil, which belongs to the technical field of chemical mass transfer and separation. Background technique [0002] Caprolactam is an important organic chemical raw material, mainly used in the production of nylon fiber and nylon resin. It is also an excellent solvent and has a wide range of applications. [0003] There are many industrial preparation methods of caprolactam, such as cyclohexane-hydroxylamine method, toluene method and so on. Due to the long reaction route, the amide oil obtained by the reaction contains various impurities. To obtain the caprolactam product, a series of physical and chemical refining methods must be adopted, such as extraction, chemical treatment and multi-effect distillation. Solvent extraction is the most effective means for the preliminary purification of caprolactam from amide oil, and benzene and toluene are the most commonly used ...

AI Technical Summary

Problems solved by technology

Compared with benzene, toluene has a lower extraction capacity for caprolactam and a higher boiling point, which limits the processing capacity of a single set of equipment, and the problem of energy and material consumption in the extraction process is more prominent

However, due to selectivity reasons, the use of benzene instead of toluene has proven to be inadvisable

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