Patent ID: 6054603
Filing Date: 2000-04-25
Classification: C07C

Abstract:
The process of recovering and purifying an unsaturated mononitrile selected from the group consisting of acrylonitrile and methacrylonitrile comprises transporting a reactor effluent containing the unsaturated mononitrile to a first column where the reactor effluent is cooled with a first aqueous stream, transporting the cooled effluent into an indirect contact cooler to condense at least some of the cooled effluent to form a condensate comprising water and at least a portion of the unsaturated mononitrile, transporting the remaining cooled gaseous effluent containing the remaining unsaturated mononitrile into a second column where the cooled effluent is contacted with a second aqueous stream to absorb substantially all of the remaining unsaturated mononitrile into the second aqueous stream, transporting the second aqueous stream containing the unsaturated mononitrile 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 unsaturated mononitrile, and transporting the partially purified unsaturated mononitrile to a third distillation column to further purify the unsaturated mononitrile, and recovering the purified unsaturated mononitrile, wherein the improvement comprises transporting the condensate formed in the indirect contact cooler to a decanter where the condensate is separated into an organic phase comprising unsaturated mononitrile, an aqueous phase and a vapor phase, and introducing the organic phase into the first distillation column without passing through the second column.