Recycling the Wastewater in the Production of Ethylenediamine

Abstract

The present work investigates the process of recycling the light fraction formed during the preparation of amines by the interaction of 1,2-dichloroethane with ammonia, by separating amines in a fractionating column. The light fraction, which is an aqueous solution containing about 1 % ethylenediamine and about 2% ammonia, is processed in an electrolyzer with a cation exchange membrane. The electrolyzer consists of two chambers. The fraction collected in the upper plate of the fractionating column was placed in the anode chamber, and distilled water was placed in the cathode chamber. It is shown that in this case a concentrate containing about 118 g/L of ethylenediamine and about 106 g/L ammonia and purified water can be produced in the cathode chamber. The concentrate can be used at the initial stages of amine production. The loss of ethylenediamine and ammonia in wastewater is virtually eliminated.