METHOD FOR ISOLATION OF OLEFIN-UNSATURATED NITRILES Russian patent published in 2003 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method for isolation and purification of olefin-unsaturated nitrile, for example, acrylonitrile. Method involves isolation of acrylonitrile from outlet flow of ammoxidation reactor obtained after catalytic reaction of ammonia and propylene containing acrylonirile, water and organic impurities and including the following steps: hardening the outlet flow from ammoxidation reactor containing acrylonitrile, water and organic impurities with an aqueous hardening flow resulting to preparing the cooled outlet flow from reactor+ADs- passing cooled outlet flow from reactor through absorber resulting to preparing underdistillate fraction from absorber that contains acrylonitrile, water and organic impurities+ADs- passing underdistillate fraction from absorber through a single fractionating column, column with removal of upper acrylonitrile-enriched distillate from which acrylonitrile is isolated and three by- side underdistillate fractions: the first by-side underdistillate fraction containing water and impurities that is fed to treatment of waste+ADs- the second by-side underdistillate fraction that represents poor acrylonitrile an aqueous flow and the third by-side underdistillate fraction that is passed through coolant and recovered on upper of column and distillating off underdistillate fraction containing organic impurities that are fed to treatment of waste. Method allows reducing the investment and exploitation consumptions. EFFECT: improved isolating method. 3 cl, 2 dwg