| 摘要 |
The invention relates to a method where the raw caprolactam is purified by hydrogenation after which it is treated in acidic medium and is distilled in alkaline medium, when: (a) 6-aminiocapronitrile is converted in raw caprolactam by reaction with water, (b) the high-boiling and low-boiling components are separated from the raw caprolactam from stage (a), (c) the raw caprilactam of stage (b) is treated with hydrogen at temperatures ranging from 50 to 150©C and from 1.5 to 250 bar in the presence of hydrogenation catalyst and optionally of solvent, thus producing mixtire A, (d1) mixture A in a solvent is passed at 30 to 80©C and from 1 to 5 bar through ion-exchange resin having and acidic groups, thus producing mixture B1, or (d2) mixture A is distilled in the presence of sulphuric acid and any amount of solvent is eliminated before the addition of the sulphuric acid, thus producing mixture B2, and mixture B1 or B2 is distilled in the presence of a base, thus producing pure caprolactam. 2 claims |
