Patents Assigned to Phillips Friedman Company
  • Patent number: 4965370
    Abstract: A process for recovering N-methyl-2-pyrrolidone from an effluent stream in a poly(arylene sulfide) process containing N-methyl-2-pyrrolidone contaminated with acidic compounds and high boiling contaminants by contacting the kettle liquid from a heavies fractionation zone with an inorganic compound selected from the group consisting of alkaline earth oxides and alkaline earth hydroxides in an amount effective to reduce the acidic compound content of the kettle liquid, and introducing the treated kettle liquid into a thin film evaporation zone to produce an overhead product containing N-methyl-2-pyrrolidone and a bottoms stream containing N-methyl-2-pyrrolidone soluble reaction products of the acidic compounds with the inorganic compound, unreacted acidic compounds and high boiling contaminants.
    Type: Grant
    Filed: August 21, 1989
    Date of Patent: October 23, 1990
    Assignee: Phillips Friedman Company
    Inventors: Kenneth D. Goetz, Bradley L. Munro