Patents by Inventor David W. Daum

David W. Daum has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Removal of hydrogenation catalyst from polymer solutions by contact with silicates
    Patent number: 5104972
    Abstract: A process is provided comprising the steps of contacting a Group VIII metal hydrogenation catalyst residue containing polymer solution with a silicate, and recovering a polymer solution comprising less than 5 ppm by weight, based on the solution, of the Group VIII metal. In a preferred embodiment, the silicate is calcium silicate, magnesium silicate or diatomaceous earth.
    Type: Grant
    Filed: November 23, 1990
    Date of Patent: April 14, 1992
    Assignee: Shell Oil Company
    Inventors: Ajay M. Madgavkar, Carma J. Gibler, David W. Daum
  • Removal of hydrogenation catalyst from polymer solutions by contact with activated carbon
    Patent number: 5089541
    Abstract: A process is provided comprising the steps of contacting a polymer solution which contains Group VIII metal hydrogenation catalyst residue with molecular oxygen, contacting the polymer solution with activated carbon, and recovering a polymer cement comprising less than 5 ppm by weight, based on the solution of Group VIII metals.
    Type: Grant
    Filed: November 23, 1990
    Date of Patent: February 18, 1992
    Assignee: Shell Oil Company
    Inventors: Ajay M. Madgavkar, David W. Daum, Carma J. Gibler