Patents by Inventor Robert G. Todd

Robert G. Todd 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).

  • Natural cresylic acid processing
    Patent number: 5354429
    Abstract: A discrete impure cresylic acid distillate fraction derived by fractional distillation of a natural cresylic acid feedstock from which tar bases and/or neutral oils have not been removed is subjected to extractive distillation with a polyhydric alcohol extractant and subsequent separation of the discrete cresylic acid fraction. The extractive distillation removes tar bases, neutral oils, undesirable phenolic substances, sulfur compounds, color-forming impurities and odor-imparting impurities.
    Type: Grant
    Filed: July 2, 1993
    Date of Patent: October 11, 1994
    Assignee: Dakota Gasification Company
    Inventors: David H. Duncan, Gene G. Baker, Dana J. Maas, Kevin M. Mohl, Robert G. Todd