A caprolactam preparation method provided in the present invention comprises the following steps: (1) in the presence of an oxime catalyst and absence of any organic solvent, conducting an ammoximation on cyclohexanone, ammonia, and hydrogen peroxide in an aqueous solvent and at a temperature between 50 and 200 °C to obtain a solvent containing a cyclohexanone oxime; (2) extracting the solvent containing the cyclohexanone oxime with an inert organic solvent to obtain an extract phase containing the cyclohexanone oxime and a raffinate phase containing the oxime catalyst and water; (3) conducting a Beckmann rearrangement reaction on the extract phase and an oleum, then conducting a neutralization reaction between a product of the Beckmann rearrangement reaction and the ammonia. The method preparing caprolactam increases a yield of the caprolactam and eliminates refining process of the cyclohexanone oxime, thus greatly shortening a manufacturing procedure and lead time, while recycling the inert organic solvent by a rearrangement reaction heat recovery.
本发明提供的一种己内酰胺制备方法包括以下步骤:(1) 在
肟催化剂存在且无任何有机溶剂的情况下,在
水性溶剂中,在 50 至 200 °C 的温度下,对
环己酮、
氨和
过氧化氢进行
氨肟化反应,得到含有
环己酮肟的溶剂;(2) 用惰性有机溶剂萃取含有
环己酮肟的溶剂,得到含有
环己酮肟的萃取相和含有
肟催化剂和
水的萃取相; (3) 在萃取相和
发烟硫酸上进行贝克曼重排反应,然后在贝克曼重排反应的产物和
氨之间进行中和反应。该己内酰胺制备方法提高了己内酰胺的收率,省去了
环己酮肟的精制过程,从而大大缩短了生产程序和交货时间,同时通过重排反应热回收利用了惰性有机溶剂。