PROCESS FOR PREPARING CAPROLACTAM FROM 6-AMINOCAPRONITRILE

摘要

The invention concerns the preparation of caprolactam by cyclizing 6aminocapronitrile in the presence of water at high temperature and optionally of a catalyst and a solvent by: a) separating from the reaction yield ("reaction yield I") of the cyclizing process caprolactam and all the components boiling higher than caprolactam ("high boilers"); b) treating the high boilers from step a) with phosphoric acid and/or polyphosphoric acid at a temperature ranging from 200 to 350 ~C, obtaining reaction yield II; and c) separating the caprolactam resulting from reaction yield II of step b) and optionally 6-aminocapronitrile from unreacted "high boilers" and the acid used.