Patents by Inventor V. N. M. Rao

V. N. M. 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).

  • Patent number: 5461177
    Abstract: A halocarbon product made from the reaction of excess hydrogen fluoride with a halocarbon, containing excess hydrogen fluoride as an azeotrope is purified by fluorination in the presence of additional halocarbon or halo-olefin.
    Type: Grant
    Filed: February 2, 1994
    Date of Patent: October 24, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Leo E. Manzer, V. N. M. Rao
  • Patent number: 5300713
    Abstract: Mixtures of halocarbons which contain fluorine and chlorine and/or bromine (e.g. a mixture of CCl.sub.2 FCF.sub.3 with CClF.sub.2 CF.sub.3, CCl.sub.2 F.sub.2, CClF.sub.2 CClF.sub.2 or CHClF.sub.2) are contacted with hydrogen in the presence of silicon carbide and/or a metal selected from aluminum, molybdenum, titanium, nickel, iron or cobalt (or their alloys) at temperatures of 350.degree. to 700.degree. C. and pressures of 0 to 1000 psig to obtain a product mixture which substantially corresponds in terms of the distribution of fluorine substituents on carbon atoms with the mixture of halocarbon starting materials.
    Type: Grant
    Filed: December 29, 1992
    Date of Patent: April 5, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: William H. Manogue, V. N. M. Rao
  • Patent number: 5136113
    Abstract: Catalytic hydrogenolysis of fluorohalocarbons (e.g., CFCs) and fluorohalohydrocarbons (e.g., HCFCs), using catalysts of Re, Co, Ni, Ru, Rh, Pd, Os, Ir, and/or Pt on a carbon having low ash content. Preferred catalysts use carbon which is acid-washed, first with an acid other than hydrofluoric acid and then with hydrofluoric acid; and also have a low content of phosphorus, sulfur, potassium, sodium and iron.
    Type: Grant
    Filed: July 23, 1991
    Date of Patent: August 4, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: V. N. M. Rao
  • Patent number: 4980324
    Abstract: This invention provides a process for the regeneration and/or activation of a noble catalyst comprising contacting said catalyst with an atmosphere comprising a fluorohalocarbon and/or a fluorohydrocarbon of the formula, C.sub.n H.sub.m F.sub.p X.sub.q, wherein X is chlorine and/or bromine; n is an integer from 1 to 6; m is an integer from 0 to 6, provided that m can be no more than the total n in the compound; p and q are integers from 1-13 when the compound is acrylic and integers from 1-11 when the compound is cyclic, provided that the fluorohalocarbon and/or fluorohalohydrocarbon always contain at least one chlorine or bromine atom and provided that m+p+q=2n+2 when the compound is acrylic and that m+p+q=2n when the compound is cyclic, at a temperature in excess of 200.degree. C.
    Type: Grant
    Filed: September 25, 1989
    Date of Patent: December 25, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Carl S. Kellner, Jan J. Lerou, V. N. M. Rao, Klaws G. Wuttke