Process for the recovery of acrylonitrile and methacrylontrile

Abstract

The process of manufacturing an unsaturated mononitrile selected from the group consisting of acrylonitrile and methacrylonitrile comprising transporting a reactor effluent containing the unsaturated mononitrile to a first column where the reactor effluent is cooled with at least one aqueous stream, transporting the cooled effluent containing the unsaturated mononitrile into a second column where the cooled effluent is contacted with at least one second aqueous stream to absorb the unsaturated mononitrile into at least one second aqueous stream, transporting the second aqueous stream containing the unsaturated mononitrile from the second column to a first distillation column for separation of the crude unsaturated mononitrile from the second aqueous stream, and transporting the separated crude unsaturated mononitrile to a second distillation column to remove at least some impurities from the crude mononitrile, and transporting the partially purified crude unsaturated mononitrile to a third distillation column (product column) to further purified the crude unsaturated mononitrile, recovering the purified unsaturated mononitrile as a sidestream from the product column, introducing about 100 to about 2000 ppm of water in the form consisting of steam and distilled water into the bottom stream obtained from the product column and recycling at least part of the product bottom stream obtained from the product column to the bottom portion of the product column. In another aspect of the present invention the steam and distilled water is added directly to the product column.