Patents by Inventor Donald E. Thomka

Donald E. Thomka 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).

  • Batch or semicontinuous pseudocumene oxidation and catalyst recovery and recycle
    Patent number: 4876385
    Abstract: A method is disclosed for the liquid-phase oxidation of pseudocumene in the presence of an oxidation catalyst comprising cobalt, manganese, and bromine components wherein the metal catalyst are recycled to the oxidation reactor in the form of their oxalates.
    Type: Grant
    Filed: March 25, 1988
    Date of Patent: October 24, 1989
    Assignee: Amoco Corporation
    Inventors: Neal R. Nowicki, Donald E. Thomka
  • Batch or semicontinuous pseudocumene oxidation and catalyst recovery and recycle
    Patent number: 4769488
    Abstract: A method is disclosed for the liquid-phase oxidation of pseudocumene in the presence of an oxidation catalyst comprising cobalt, manganese, and bromine components wherein the metal catalyst are recycled to the oxidation reactor in the form of their oxalates.
    Type: Grant
    Filed: October 23, 1985
    Date of Patent: September 6, 1988
    Assignee: Amoco Corporation
    Inventors: Neal R. Nowicki, Donald E. Thomka
  • Aged molten color of maleic anhydride
    Patent number: 4260546
    Abstract: The oxidation of butane vapor with air produces an impure maleic anhydride which when fractionated to first remove materials boiling lower than maleic anhydride and then a maleic anhydride product, leads to a maleic anhydride product fraction which when held at 140.degree. C. for 90 minutes discolors and is not a commercially acceptable product. Such discoloration can be substantially reduced by maintaining the impure maleic anhydride at a temperature from 60.degree. up to 200.degree. C. in the presence of small amounts of either hydrogen peroxide and/or sulfuric acid.
    Type: Grant
    Filed: December 26, 1979
    Date of Patent: April 7, 1981
    Assignee: Standard Oil Company (Indiana)
    Inventors: Hobe Schroeder, Donald E. Thomka