Patents by Inventor Dharamvir Punwani

Dharamvir Punwani 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: 4954246
    Abstract: A process for slurry-phase gasification of carbonaceous feedstock materials is provided wherein feedstock materials are combined with a liquid to form a feedstock slurry. Product gases are formed from the feedstock slurry in a gasifier reaction vessel in the presence of elevated temperatures and pressures and ultrasonic energy. Gasification catalysts may be utilized to provide increased reaction rates. The process of the present invention provides enhanced conversion of carbonaceous solids feedstock to gaseous products comprising primarily methane and carbon dioxide with some higher organic liquids.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: September 4, 1990
    Assignee: Institute of Gas Technology
    Inventors: Dharamvir Punwani, Michael C. Mensinger
  • Patent number: 4579562
    Abstract: A process and apparatus for thermochemical beneficiation of carbonaceous solids, such as low rank coals and biomass, by countercurrently passing a moving bed of the solids in contact with a liquid in an amount sufficient to flush product liquids having dissolved and suspended products and make-water from the moving bed which is maintained within the wet carbonization reaction zone at about 400.degree. to about 650.degree. and an elevated pressure sufficient to prevent boiling of the liquid. The feed liquid may be preheated in a lower liquid preheat zone of the moving bed and a substantial portion of the liquid removed as heat recovery liquid for other process uses. External heat may be added in the lower portion of the wet carbonization reaction zone.
    Type: Grant
    Filed: May 16, 1984
    Date of Patent: April 1, 1986
    Assignee: Institute of Gas Technology
    Inventors: Paul B. Tarman, Dharamvir Punwani
  • Patent number: 4336125
    Abstract: A process and apparatus for production of synthetic hydrocarbon fuels from peat providing wide variation of the composite proportion of liquid-gas output while maintaining high overall carbon conversion to useful fuel. The process and apparatus utilizes three process stages in a single vessel providing functions of drying wet peat, provisions for addition of both wet and dry peat to a hydropyrolysis zone and gasification of the peat char.
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: June 22, 1982
    Assignee: Institute of Gas Technology
    Inventors: Sanford A. Weil, Dharamvir Punwani, William W. Bodle
  • Patent number: 4263125
    Abstract: A process and apparatus for production of synthetic hydrocarbon fuels from peat providing wide variation of the composite proportion of liquid-gas output while maintaining high overall carbon conversion to useful fuel. The process and apparatus utilizes three process stages in a single vessel providing functions of drying wet peat, provisions for addition of both wet and dry peat to a hydropyrolysis zone and gasification of the peat char.
    Type: Grant
    Filed: July 20, 1979
    Date of Patent: April 21, 1981
    Assignee: Institute of Gas Technology
    Inventors: Sanford A. Weil, Dharamvir Punwani, William W. Bodle
  • Patent number: 4223449
    Abstract: Water is removed from a hydrocarbonaceous solid such as peat by contacting the solid with a liquid solvent relatively free of moisture such as benzene or toluene at elevated temperatures, i.e. 200.degree.-600.degree. F. and preferably at elevated pressures to prevent excessive volatilization, i.e. pressures of about 1 to about 100 atmospheres, to transfer at least a portion of the moisture in the solid to the solvent. The solvent is further characterized by its relative inability to dissolve appreciable amounts of water at low or ambient temperatures and its ability to dissolve substantially greater amounts of water at higher temperatures, i.e. 200.degree.-600.degree. F. After the solids are contacted with the solvent and while the solids and solvent are still at an elevated temperature, at least a portion of the solvent, now containing dissolved water, is removed from the solids to provide a product solids having a diminished water content.
    Type: Grant
    Filed: June 27, 1979
    Date of Patent: September 23, 1980
    Assignee: Institute of Gas Technology
    Inventors: William W. Bodle, Dharamvir Punwani
  • Patent number: 4003821
    Abstract: A process for producing hydrocarbon liquids in preference to gases from oil shale. The shale is introduced at the top of a reaction chamber which includes an upper oil shale preheat zone having a temperature not more than about 950.degree. F., a hydroretort reaction zone at a temperature of about 850.degree. to about 1250.degree. F. and a lower hydrogen preheat zone to recover heat from spent shale. Solids from the shale are passed downwardly through the chamber so that the shale, and particularly the oil therein, is gradually heated to the reaction temperature over a relatively extended period of at least ten minutes so as to inhibit the formation of a carbon residue. A hydrogen-rich gas, containing hydrogen in excess of stoichiometric amounts needed for the hydroretorting of the oil in the shale, is passed upwardly in the reaction chamber and countercurrent to the shale solids passing downwardly therethrough.
    Type: Grant
    Filed: August 18, 1975
    Date of Patent: January 18, 1977
    Assignee: Institute of Gas Technology
    Inventors: Sanford A. Weil, Paul B. Tarman, Dharamvir Punwani