PROCESS FOR THE PREPARATION OF CAPROLACTAM

摘要

Process for the preparation of caprolactam in which there is formed an ammonium sulphate solution from which ammonium sulphate crystals and a condensate are obtained in a crystallisation step, with the condensate being purified and returned to the production process for caprolactam. The ammonium sulphate solution preferably is formed during neutralisation of the rearrangement mixture with ammonia or aqueous ammonia, which rearrangement mixture is obtained during the formation of caprolactam from cyclohexanone oxime through a Beckmann rearrangement in the presence of sulphuric acid.