The method for purifying 1,2-propanediamine

The present invention discloses a process for purifying 1,2-propanediamine, the use of C2-C5 diols or triol or a C2-C5 alcohol amine of one or dimethylsulfoxide or N- methylpyrrolidone as the extraction agent after the crude 1,2-propanediamine and extraction agent extraction through the extraction column, the top of the extraction column produced water extraction column bottoms material into the distillation column is rectified after , distillation top product 1,2-propanediamine, the isolated 1,2-propanediamine and the water in the preparation process, the use of the extractant and reduce the reflux ratio of column height, improved separation efficiency extraction agent after a simple separation can be reused, significantly reducing power consumption, reducing production costs. High separation efficiency and high purity product is purified, colorless, transparent products, recyclable extractant advantages.