Patents by Inventor Richard D. Doctor

Richard D. Doctor 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: 11479524
    Abstract: A method and system for membrane-assisted production of high purity concentrated dimethyl carbonate by the reaction of carbon dioxide and methanol is provided. Carbon dioxide is recovered from flue gas or other dilute streams from industrial processes by a membrane and subsequent conversion takes place to an intermediate methyl carbamate by reacting of carbon dioxide with ammonia and methanol. For high-purity carbon dioxide obtained by one of the carbon capture technologies or by a process (such as, for example, ethanol fermentation process) the membrane reactor is replaced with a catalytic reactor for direct conversion of carbon dioxide to methyl carbamate by reacting with ammonia and methanol. The methyl carbamate is further reacted with methanol for conversion to dimethyl carbonate. An integrated reactive distillation process using side reactors is used for facilitating the catalytic reaction in the subject method for producing high purity dimethyl carbonate.
    Type: Grant
    Filed: October 11, 2019
    Date of Patent: October 25, 2022
    Assignee: E3TEC SERVICES, LLC
    Inventors: Chandrakant B. Panchal, Richard D. Doctor
  • Patent number: 8247009
    Abstract: The present invention provides a method for generating methane from a carbonaceous fuel source with simultaneous sequestration of carbon dioxide, the method comprising anaerobically incubating a particulate alkaline earth metal salt in contact with a particulate and/or dissolved carbonaceous feedstock in a neutral or alkaline aqueous culture medium containing a culture of methanogenic bacteria consortia and collecting methane generated therefrom. At least a portion of carbon dioxide produced during the incubation reacts with the alkaline earth metal salt to form an alkaline earth metal carbonate, thereby sequestering the carbon dioxide.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: August 21, 2012
    Assignee: UChicago Argonne, LLC
    Inventors: Rathin Datta, Seth W. Snyder, Richard D. Doctor, Michael P. Henry
  • Publication number: 20100093049
    Abstract: The present invention provides a method for generating methane from a carbonaceous fuel source with simultaneous sequestration of carbon dioxide, the method comprising anaerobically incubating a particulate alkaline earth metal salt in contact with a particulate and/or dissolved carbonaceous feedstock in a neutral or alkaline aqueous culture medium containing a culture of methanogenic bacteria consortia and collecting methane generated therefrom. At least a portion of carbon dioxide produced during the incubation reacts with the alkaline earth metal salt to form an alkaline earth metal carbonate, thereby sequestering the carbon dioxide.
    Type: Application
    Filed: September 24, 2009
    Publication date: April 15, 2010
    Applicant: UChicago Argonne, LLC
    Inventors: Rathin Datta, Seth W. Snyder, Richard D. Doctor, Michael P. Henry
  • Patent number: 5250482
    Abstract: A process for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded.
    Type: Grant
    Filed: August 20, 1992
    Date of Patent: October 5, 1993
    Assignee: University of Chicago
    Inventor: Richard D. Doctor
  • Patent number: 4778594
    Abstract: The present invention relates to methods and apparatus for segregating paramagnetic from diamagnetic particles in particulate material and, in particular, to the open gradient magnetic separation of ash producing components and pyritic sulfur from coal. The apparatus includes a vertical cylinder and a rotatable vertical screw positioned within the cylinder, the screw having a helical blade angled downwardly and outwardly from the axis. Rotation of the vertical screw causes denser particles, which in the case of coal include pyritic sulfur and ash, which are paramagnetic, to migrate to the outside of the screw, and less dense particles, such as the low sulfur organic portion of the coal, which are diamagnetic, to migrate towards the center of the screw. A vibration mechanism attached to the screw causes the screw to vibrate during rotation, agitating and thereby accommodating further segregation of the particles.
    Type: Grant
    Filed: July 24, 1986
    Date of Patent: October 18, 1988
    Assignee: The University of Chicago (Arch Development Corp.)
    Inventor: Richard D. Doctor
  • Patent number: 4612175
    Abstract: A method of simultaneously removing SO.sub.2 and NO from oxygen-containing flue gases resulting from the combustion of carbonaceous material by contacting the flue gas with an aqueous scrubber solution containing an aqueous sulfur dioxide sorbent and an active metal chelating agent which promotes a reaction between dissolved SO.sub.2 and dissolved NO to form hydroxylamine N-sulfonates. The hydroxylamine sulfonates are then separated from the scrubber solution which is recycled.
    Type: Grant
    Filed: August 5, 1985
    Date of Patent: September 16, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: John B. L. Harkness, Richard D. Doctor, Ronald J. Wingender