Patents by Inventor Raam R. Mohan

Raam R. Mohan 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).

  • Method for the recovery of a tungsten-containing catalyst from coke containing nickel and vanadium
    Patent number: 4501820
    Abstract: A tungsten-containing catalyst associated with coke containing vanadium and nickel is recovered by a method which includes steam gasification, low temperature burning to remove at least a portion of the coke and selective extraction of the nickel and vanadium.
    Type: Grant
    Filed: July 28, 1983
    Date of Patent: February 26, 1985
    Assignee: Exxon Research & Engineering Co.
    Inventors: David E. Allan, Byron V. Molstedt, Raam R. Mohan
  • Regeneration of spent hydrodesulfurization catalyst with heteropoly acids
    Patent number: 4272401
    Abstract: Contacting deactivated hydrodesulfurization catalyst, such as Co-Mo supported on alumina, with a heteropoly acid, such as molybdophosphoric acid or tungstosilicic acid, in pH range of about 1 to 3 and temperature range of about 20.degree. to 80.degree. C., results, before any coke is burned off the catalyst, in selective abstraction of vanadium and nickel, removal of sulfur, increase in surface area, and increase in pore volume of the catalyst. Subsequent cobalt doping of demetallized catalyst followed by calcination promotes decoking, additional sulfur removal and additional increase in surface area and pore volume. The process results in substantially complete regeneration of catalytic activity.
    Type: Grant
    Filed: July 19, 1979
    Date of Patent: June 9, 1981
    Assignee: Exxon Research & Engineering Co.
    Inventors: Raam R. Mohan, Gopal H. Singhal
  • Regeneration of spent hydrodesulfurization catalysts employing presulfiding treatment and heteropoly acids
    Patent number: 4272400
    Abstract: The removal of metals, especially vanadium, from spent hydrofining catalyst is accomplished by a two-step process. Treatment with a gaseous sulfur-containing reagent brings the metals to the surface of the catalyst and converts them to sulfides, which are then efficiently removed by contact with a heteropoly acid such as molybdophosphoric acid. Treatment of deactivated hydrodesulfurization catalysts such as Co-Mo supported on alumina by this process results in substantially complete regeneration of catalytic activity.
    Type: Grant
    Filed: July 19, 1979
    Date of Patent: June 9, 1981
    Assignee: Exxon Research & Engineering Co.
    Inventors: Bernard G. Silbernagel, Raam R. Mohan, Gopal H. Singhal
  • Regeneration of spent hydrodesulfurization catalysts with heteropoly acids and hydrogen peroxide
    Patent number: 4268415
    Abstract: Contacting deactivated hydrodesulfurization catalyst, such as Co-Mo supported on alumina, with a heteropoly acid, such as molybdophosphoric acid or tungstosilicic acid, to which dilute hydrogen peroxide is added, results in a significant enhancement in the rate and extent of carbon and metals removal. Forms of deposited vanadium intractable by other treatments are also removed. The process results in substantially complete regeneration of catalytic activity.
    Type: Grant
    Filed: July 19, 1979
    Date of Patent: May 19, 1981
    Assignee: Exxon Research & Engineering Co.
    Inventors: Raam R. Mohan, Bernard G. Silbernagel, Gopal H. Singhal
  • Use of microorganisms in combination with surface active agents to synergistically disperse oil slicks
    Patent number: 4146470
    Abstract: A method of preparation and application of a composition comprising specified microorganisms in combination with surfactants for a synergistic dispersal of oil slicks.
    Type: Grant
    Filed: July 22, 1977
    Date of Patent: March 27, 1979
    Assignee: Exxon Research & Engineering Co.
    Inventors: Raam R. Mohan, Max L. Robbins, Allen I. Laskin, Lars A. Naslund