METHOD OF SIMULTANEOUSLY PREPARING CAPROLACTAM AND HEXAMETHYLENE DIAMINE Russian patent published in 2000 - IPC

FIELD: chemical industry. SUBSTANCE: adipodinitrile is partially hydrogenated to produce mixture comprising basically 6-aminocapronitrile, hexamethylene diamine, ammonia, adipoditrile and hexamethylene diamine and 6-aminocapronitrile are then isolated from said mixture by distillation, 6- aminocapronitrile is cyclized into caprolactam. From hydrogenation stage, ammonia is separated incompletely by distillation to isolate stillage product I comprising predominantly 6-aminocapronitrile, hexamethylene diamine, adipodinitrile and hexamethylene imine. Distillation is carried out in the presence of inert material A. Stillage product I is then distilled to produce mixture of inert material A and ammonia in the form of overhead product, and stillage product II comprising predominantly 6-aminocapronitrile, hexamethylene diamine, adipodinitrile, hexamethylene imine, and inert material A. In 3rd column, material A in the form of overhead product and stillage product III are isolated from stillage product II. Stillage product III is distilled in fourth column to produce overhead product comprising predominantly hexamethylene imine directed optionally to be further purified to fifth column in which hexamethylene imine and stillage product V comprising predominantly hexamethylene imine with purity of at least 95% is produced from column top. Fourth column stillage product comprising predominantly 6-aminocapronitrile and adipodinitrile is distilled off in sixth column to produce 6-aminocapronitrile overhead product with purity of at least 95% which is then cyclized to form coprolactam. One process combines double-stage process for preparing caprolactam. One process combines double- stage process for preparing caprolactam from adiponitrile to produce simultaneously 6-aminocapronitrile and carry out cyclization thereof. EFFECT: more efficient preparation method. 6 cl, 2 ex, 1 dwg