摘要 |
A lactam of high purity is recovered by using three distillation columns. A lactam is purified by cyclizing hydrolysis of an aminonitrile which consists of the elimination of ammonia and possibly solvent. The lactam is then recovered by distillation in the presence of a base, and from the distillation is recovered a head fraction comprising compounds more volatile than the lactam, a fraction comprising the lactam of high purity and a tail fraction comprising a lactam and compounds of boiling points greater than the lactam. The tail fraction is treated to recover most of the lactam which is recycled. An INDEPENDENT CLAIM is also included for the installation to effect the process. |