Patents by Inventor V. N. Mallikarjuna Rao

V. N. Mallikarjuna Rao 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).

  • Catalyzed hydrofluorination of alkenes
    Patent number: 5015791
    Abstract: Process for the preparation of fluorinated alkanes by contacting alkenes with HF in the presence of TaCl.sub.2 or TaBr.sub.5.
    Type: Grant
    Filed: August 22, 1990
    Date of Patent: May 14, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: V. N. Mallikarjuna Rao
  • Gas-phase fluorination process
    Patent number: 5008475
    Abstract: An improved gas-phase process for the manufacture of 1,1,1-trifluorodichloroethane and/or 1,1,1,2-tetrafluorochloroethane by contacting a suitable tetrahaloethylene with hydrogen fluoride in the presence of a selected metal in combination with a high fluorine content aluminum-containing compound, the reaction being conducted under controlled conditions whereby the production of pentafluoroethane is minimized.
    Type: Grant
    Filed: January 16, 1990
    Date of Patent: April 16, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao
  • Process for the preparation of 1,1,1,2-tetrafluoroethane
    Patent number: 5008476
    Abstract: Improved process for the preparation of 1,1,1,2-tetrafluoroethane by the steps of chlorofluorination of selected organic compounds using Cl.sub.2 and HF followed by hydrogenolysis of the resulting products, the improvement residing in the use of excess HF and recycle of the unreacted compounds and byproducts to the chlorofluorination step.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: April 16, 1991
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao
  • Purification of saturated halocarbons
    Patent number: 5001287
    Abstract: A process for treating an impure mixture consisting essentially of at least one olefinic impurity and at least one saturated halocarbon selected from fluorocarbons and fluorohydrocarbons by contacting the mixture with a source of hydrogen in the presence of a hydrogenation catalyst, whereby the olefinic impurity is converted to a hydrogenated form thereof, to produce a treated mixture consisting essentially of the hydrogenated form of the olefinic impurity or impurities and the saturated halocarbon or halocarbons from the impure mixture.
    Type: Grant
    Filed: February 2, 1989
    Date of Patent: March 19, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Richard E. Fernandez, V. N. Mallikarjuna Rao
  • Process for the separation of HF via Azeotropic distillation
    Patent number: 4944846
    Abstract: Process for the separation of hydrogen fluoride (HF), 2,2-dichloro-1,1,1-trifluoroethane (FC-123), and/or 2-chloro-1,1,1,2-tetrafluoroethane (FC-124) from mixtures containing them by controlling the molar ratio of HF/FC-123 in the mixture prior to subjecting the mixture to azeotropic distillation.
    Type: Grant
    Filed: August 1, 1988
    Date of Patent: July 31, 1990
    Assignee: E. I. DuPont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao, Richard T. Rockwell, Michael A. Sisk, Edwin J. Warwas, Roy Winteringham
  • Process for the separation of HF via phase separation and distillation
    Patent number: 4911792
    Abstract: Process for the separation of HF, 2,2-dichloro-1,1,1-trifluoroethane (FC-123) and/or 2-chloro-1,1,1,2-tetrafluoroethane (FC-124) mixture by subjecting the mixture to a temperature from about -80.degree. C. to about 40.degree. C. and a pressure from about 0.10 MPa to about 3.55 MPa in a separation zone, whereby an organic phase having less than 15 mole percent of HF is formed as the bottom layer in the separation zone and an acid phase having at least 93 mole percent of HF is formed at the top in the separation zone.
    Type: Grant
    Filed: August 1, 1988
    Date of Patent: March 27, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao, Richard T. Rockwell, Michael A. Sisk, Edwin J. Warwas, Roy Winteringham
  • Isomerization of saturated fluorohydrocarbons
    Patent number: 4902838
    Abstract: A process for isomerizing saturated C.sub.2 to C.sub.6 fluorohydrocarbons having lesser thermodynamic stability to fluorohydrocarbons having greater thermodynamic stability comprising contacting in the gaseous phase at a temperature from about 200.degree. C. to about 475.degree. C. at least one C.sub.2 to C.sub.6 saturated fluorohydrocarbon with a catalyst composition comprising an aluminum fluoride.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: February 20, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao
  • Hydrodehalogenation of CF.sub.3 CHClF in the presence of supported Pd
    Patent number: 4873381
    Abstract: Process for the manufacture of 1,1,1,2-tetrafluoroethane by the vapor phase hydrodehalogenation of 1,1,1,2-tetrafluorochloroethane in the presence of a catalyst consisting essentially of palladium on an aluminum fluoride or fluorinated alumina support.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: October 10, 1989
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Carl S. Kellner, V. N. Mallikarjuna Rao
  • Process for the manufacture of 1,1,1-trifluorodichloroethane and 1,1,1,2-tetrafluorochloroethane
    Patent number: 4843181
    Abstract: An improved gas-phase process for the manufacture of 1,1,1-trifluorodichloroethane and/or 1,1,1,2-tetrafluorochloroethane by contacting a suitable tetrahaloethylene and/or pentahaloethane with hydrogen fluoride in the presence of Cr.sub.2 O.sub.3, prepared by pyrolysis of (NH.sub.4).sub.2 Cr.sub.2 O.sub.7, the reaction being conducted under controlled conditions whereby the production of pentafluoroethane is minimized.
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: June 27, 1989
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: William H. Gumprecht, Leo E. Manzer, V. N. Mallikarjuna Rao
  • Gas-phase fluorination process
    Patent number: 4766260
    Abstract: An improved gas-phase process for the manufacture of 1,1,1-trifluorodichloroethane and 1,1,1,2-tetrafluorochloroethane by contacting a suitable tetrahaloethylene with hydrogen fluoride in the presence of a selected metal on a high fluorine content alumina support, the reaction being conducted under controlled conditions whereby the production of pentafluoroethane is minimized.
    Type: Grant
    Filed: July 7, 1987
    Date of Patent: August 23, 1988
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao
  • Gas-phase fluorination process
    Patent number: 4766259
    Abstract: An improved gas-phase process for the manufacture of 1,1-difluoro-1,2-dichloroethane and 1-fluoro-1,1,2-trichloroethane by contacting a suitable trihaloethylene and/or a tetrahaloethane with hydrogen fluoride in the presence of a metal in combination with a high fluorine content alumina, the reaction being preferably conducted under controlled conditions whereby the production of 1,1,1-trifluorochloroethane is minimized.
    Type: Grant
    Filed: August 13, 1987
    Date of Patent: August 23, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. Mallikarjuna Rao
  • Process for oxidation of methanol to formaldehyde with nitrous oxide
    Patent number: 4233248
    Abstract: Formaldehyde is synthesized by continuously passing a gaseous mixture of methanol and nitrous oxide over a metallic silver-containing catalyst bed at a temperature of about 475 to about 675.degree. C.
    Type: Grant
    Filed: February 21, 1979
    Date of Patent: November 11, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: V. N. Mallikarjuna Rao, Stanislaw B. Ziemecki
  • Methanol oxidation/dehydrogenation over silver-gold alloy
    Patent number: 4219509
    Abstract: This invention relates to a process for the catalytic conversion of methanol to formaldehyde by oxidation/dehydrogenation over a silver-gold alloy catalyst.
    Type: Grant
    Filed: January 23, 1978
    Date of Patent: August 26, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Norman A. Nielsen, V. N. Mallikarjuna Rao