Patent ID: 9518024
Filing Date: 2016-12-13
CPC Classification: B01D,B01J,C07D

Claim Text:
1. A method for preparing caprolactam, comprising steps of: (a) subjecting cyclohexanone oxime and sulfuric acid to a Beckmann rearrangement reaction to obtain a rearrangement mixture; (b) neutralizing the rearrangement mixture with a base to obtain a first crude caprolactam solution rich in caprolactam and a second crude caprolactam solution rich in sulfate; (c) extracting at least the first crude caprolactam solution with an organic solvent to obtain a caprolactam organic solution; (d) mixing the caprolactam organic solution with hydrogen to perform a hydrogenation reaction in a hydrogenation reactor having a hydrogenation catalyst, wherein a weight hourly space velocity of the caprolactam organic solution is 1 to 20 per hour, a feeding hydrogen flow rate is NM (e) purifying the hydrogenated caprolactam organic solution, wherein the purification includes steps of evaporation and distillation to separate the caprolactam.