Purification of ţ-caprolactam by crystallization

Abstract

Purification of ţ-caprolactam by crystallization from trichloroethylene has been experimentally studied. Physical properties of the caprolactam-trichloroethylene system and its relevant crystallization characteristics were determined. Evaporative crystallization realized in an air-lift type of crystallizer was selected at the best mode of crystallization. Bench- scale model of such crystallizer of 16 l volume was constructed and its performance with the studied system was tested. Based on the data obtained from the model crystallization experiments a full-scale crystallizer of 100 m3 volume was designed , built and successfully put into operation.