Patents by Inventor Allen T. Chang

Allen T. Chang 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).

  • Patent number: 5183538
    Abstract: A method for recovering a liquid diluent having a low salt content from an organic/aqueous mixture which contains significant quantities of the diluent, an alkali metal salt, and water comprises an integrated process which joins extraction and ion exchange steps and a reaction for the conversion of an alkali metal hydroxide. In the initial step the diluent is extracted from the original mixture employing a suitable extractant material. The extract from the initial step containing diluent, extractant material, along with reduced quantities of water and salt, is passed to an ion exchange column for conversion of the alkali metal salt to its hydroxide. In a following fractional distillation dewatering column the diluent begins to react with the alkali metal hydroxide to form an alkali-metal salt of aminocarboxylic acid which can pass harmlessly through the dewatering column for removal in further following fractional distillation step.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: February 2, 1993
    Assignee: Phillips Petroleum Company
    Inventors: Lacey E. Scoggins, Fu M. Lee, Allen T. Chang, Wiley D. Perkins