DISTILLATIVE METHOD FOR SEPARATING HEXAMETHYLENEDIAMINE FROM A MIXTURE COMPRISING HEXAMETHYLENEDIAMINE, -AMINOCAPRONITRILE AND TETRAHYDROAZEPINE

摘要

A method for recovering hexamethylene diamine (HMD) from a mixture (18) comprising HMD, 6-aminocapronitrile (ACN) tetrahydroazepine (THA), and ADN comprising: (a) introducing the mixture into a distillation column (20) capable of separating as a group the HMD, ACN and at least a portion of the THA from the ADN, while minimizing the isomerization of the ADN into CPI; and (b) introducing the HMD, ACN and at least a portion of the THA into a distillation column (26) capable of separating the HMD from the ACN in such a way that the THA separates along with the ACN.