METHOD FOR THE DISTILLATIVE PURIFICATION OF EDA

摘要

The invention relates to a method for the distillative purification of ethylenediamine (EDA), having the steps a) and b). In step a) a mixture (G1) containing water, EDA, and N-methyl ethylenediamine (N-MeEDA) is supplied into a distillation device (D1) from which the main quantity of the water contained in the mixture (G1) is separated via the head at a pressure of more than 4.8 barA. The water-depleted mixture (G2) is supplied from the sump of (D1) to a distillation device (D2) in step b), and the main quantity of N-MeEDA is distilled out via the head of (D2). The stream S3 obtained from the sump of (D2) contains EDA. The components of water and N-MeEDA contained in the mixture (G1) are largely or completely depleted. Optionally, additional distillation steps can be carried out in order to obtain pure EDA if additional diethylenetriamine (DETA) is contained in the mixture (G1) for example. As long as additional ammonia is contained in the mixture (G1), an ammonia separation process is additionally carried out in the method according to the invention preferably prior to carrying out step a).