公开(公告)号：US3839408A

公开(公告)日：1974-10-01

申请号：US29263472

申请日：1972-09-27

Applicant: BASF AG

Inventor： AREND W ,  EISFELD K ,  HAUG P ,  WEGERICH A ,  HIMMELHAN E ,  SCHOLZ H

IPC: C07C255/04 ,  C07C20060101 ,  C07C67/00 ,  C07C253/00 ,  C07C253/34 ,  C07C121/26

CPC classification number: C07C255/00

Abstract: 1. A PROCESS FOR THE CONTINUOUS PURIFICATION OF ADIPONITRILE BY CONTINUOUSLY PASSING THE ADIPONITRILE TO BE PURIFIED THROUGH A CRYSTALLIZING ZONE WITH COOLING THEREOF SO THAT A SUSPENSION OF FINELY DIVIDED SOLID ADIPONITRILE IN MOLTEN ADIPONITRILE IS FORMED SEPARATING THE SOLID ADIPONITRILE FROM THE MOLTEN ADIPONITRILE, WASHING THE SOLID DINTRILE WITH LIQUID ADIPONITRILE AND RECOVERING PURE ADIPONITRILE CRYSTALS, AND RETURNING THE SEPARATED ADIPONITRILE MOTHER LIQUID TO THE CRYSTALLIZING ZONE WHEREIN THE COOLING OF THE ADIPONITRILE TO BE PURIFIED IS CARRIED OUT INDIRECTLY BY EVAPORATING LIQUID AMMONIA WHICH IS PASSED THROUGH A COOLING JACKET OF SAID CRYSTALLIZATION ZONE, THE AMOUNT BY WEIGHT OF LIQUID AMMONIA PASSED THROUGH THE COOLING JACKET PER UNIT TIME BEING ONE TO FIVE TIMES THE AMOUNT OF AMMMONIA, AS HEAT OF EVAPORATION THEREOF, NECESSARY TO ABABSORB THE HEAT EVOLVED BY THE CRYSTALLIZATION OF ADIPONITRILE IN SAID ZONE, AND THE MOTHER LIQUOR OBTAINED AFTER SEPARATION OF THE SOLID DINITRILE OBTAINED IS SEPARATED INTO TWO UNEQUAL PORTIONS OF 55-90% AND 1045% BY WEIGHT OF THE TOTAL MOTHER LIQUOR OF WHICH THE LARGER PORTION IS RETURNED IMMEDIATELY TO THE CRYSTALLIZATION ZONE AND THE SMALLLER PORTION IS DISTILLED BEFORE IT IS RETURNED TO THE CRYSTALLIZATION ZONE.