Patents Examined by V. Manohoran
  • Process for refining ethylene glycol
    Patent number: 4830712
    Abstract: A process is described for recovering polyester-grade ethylene glycol from crude ethylene glycol containing at least one component which has a normal boiling point below that of ethylene glycol, and which can form a UV absorber in the presence of ethylene glycol which comprises supplying to an ethylene glycol distillation system, preferably comprising a fractional distillation zone having an upper portion, a lower portion and an intermediate portion a crude ethylene glycol stream at a determined pH of less than about 7.
    Type: Grant
    Filed: September 29, 1987
    Date of Patent: May 16, 1989
    Assignee: Union Carbide Corporation
    Inventors: John W. Crandall, Bernard C. Ream