Patents Assigned to Davy Research and Development Limited
  • Patent number: 5426207
    Abstract: A diaryl carbonate is produced by transesterification of a dialkyl carbonate, such as dimethyl carbonate, with an aromatic hydroxy compound, such as phenol, in three successive reaction zones. A transesterification catalyst, such as a titanate ester or ester mixture is used in each zone. Conditions are selected to maximize formation of alkyl aryl carbonate in the first and second reaction zones, while conversion to diaryl carbonate is favored in the third reaction zone. The vaporous mixture from the first two reaction zones is a mixture containing alkyl alcohol, dialkyl carbonate, alkyl aryl carbonate and aromatic hydroxy compound. This mixture is separated in an alkyl alcohol recovery zone by distillation in the distillation columns to produce useful recycle streams.
    Type: Grant
    Filed: October 28, 1993
    Date of Patent: June 20, 1995
    Assignee: Davy Research and Development Limited
    Inventors: George E. Harrison, Alan J. Dennis, Mohammad Sharif