GB813163A - Extraction of amines - Google Patents

Abstract

Diamines and higher polyamines, e.g. those obtained by reaction of dichlorinated alkanes with ammonia, are extracted from aqueous solutions of their hydrochlorides by contacting the solution with an ion exchange material, washing the ion exchange material with water, regenerating it in any known manner, extracting the amines from the solution by direct distillation, and re-cycling the solution obtained from the washing stage. Suitable resins are anion exchangers, such as quaternary ammonium resins, in the OH form, and cation exchangers, such as those containing sulphonic acid groups, in the H form or in the salt form. When using cation exchangers the amines are adsorbed on the resin as salts and are eluted with an alkaline solution. In examples the mixture obtained by reacting dichloroethane with ammonia is treated with (1) the quaternary ammonium resin Amberlite 1R410; (2), (3) the sulphonic acid type resin Amberlite IR120 in the acid form; (4)-(8) Amberlite IR120 in the sodium salt form ("Amberlite" is a Registered Trade Mark). Example (9) describes the separation of ethylenediamine by distillation from its solution containing caustic soda obtained in Examples (2)-(8).