Patents by Inventor Chaya Venkat

Chaya Venkat 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: 5292880
    Abstract: A process for catalytically converting cyclohexanone oxime to epsilon caprolactam. The conversion catalyst is a crystalline aluminosilicate zeolite having a Constraint Index greater than 1 and a reduced surface acidity. The surface acidity is reduced by selective surface dealumination of the crystalline aluminosilicate zeolite by contacting the zeolite with dicarboxylic acid, such as oxalic acid.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: March 8, 1994
    Assignee: Mobil Oil Corporation
    Inventors: Minas R. Apelian, Weldon K. Bell, Anthony S. Fung, Werner O. Haag, Chaya Venkat
  • Patent number: 4908341
    Abstract: A method for regenerating a spent porous crystalline catalyst, optionally associated with a metal component such as noble and/or base metal(s), is described. The method comprises contacting the spent catalyst which has become deactivated by accumulation of carbonaceous residue with one or more light aromatic compounds under conditions resulting in reactivation of said catalyst. The light aromatic compounds employed are ones which have the capability of penetrating the catalyst, so as to contact the carbonaceous residue contained therein, undergoing alkylation by alkyl fragments contributed by components of the carbonaceous residue and diffusing from or otherwise escaping the catalyst.
    Type: Grant
    Filed: October 20, 1987
    Date of Patent: March 13, 1990
    Assignee: Mobil Oil Corp.
    Inventors: Ann L. Pruden, Chaya Venkat, Darrell D. Whitehurst
  • Patent number: 4892646
    Abstract: A method for treating a porous crystalline catalyst optionally associated with a metal component such as a noble and/or base metal(s) is described. The method comprises contacting the catalyst with a low molecular weight aromatic compound under coking conditions. Such a treatment method increases the cycle length and the useful life of the catalyst. Using the treated catalyst in a dewaxing process and regenerating the catalyst by treating with hydrogen and a low molecular weight hydrocarbon.
    Type: Grant
    Filed: May 2, 1988
    Date of Patent: January 9, 1990
    Assignee: Mobil Oil Corporation
    Inventors: Chaya Venkat, Darrell D. Whitehurst
  • Patent number: 4871444
    Abstract: A method for improving the cetane number of an aromatic hydrocarbon oil such as FCC light cycle oil and thereby increase its value as a blending stock for diesel fuel or heating oil. In one embodiment, the FCC light cycle oil is alkylated in the presence of a solid acidic catalyst and with a linear mono-olefin having a chain length of at least five carbon atoms. In another embodiment, the light cycle oil is alkylated with an olefin having three to nine carbon atoms or a mixture thereof and with ZSM-20 as catalyst to decrease the frequency of catalyst regeneration.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: October 3, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Nai Y. Chen, Billy K. Huh, Anil B. Ketkar, Chaya Venkat
  • Patent number: 4830729
    Abstract: Catalytic dewaxing of wax containing hydrocarbon feedstocks is undertaken in the presence of a catalyst composition comprising a dehydrogenation metal in combination with a non-acidic microporous crystalline material to maximize liquid yield.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: May 16, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Ralph M. Dessau, Ernest W. Valyocsik, Chaya Venkat
  • Patent number: 4828678
    Abstract: In the cataytic cracking of gas oils or heavier feeds, retarded catalyst aging is achieved by adding lighter saturated hydrocarbons such as paraffins and/or cycloparaffins to the feed together with employing a highly siliceous zeolite as the cracking catalyst. The unconverted light hydrocarbon may be recovered and recycled. The invention is applicable to fluid catalytic cracking for the manufacture of gasoline and light fuel oil, and also to the catalytic dewaxing process wherein normal paraffins are selectively cracked to reduce the pour point of a fuel oil or of a lubricant based stock.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: May 9, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Chaya Venkat, Darrell D. Whitehurst
  • Patent number: 4549815
    Abstract: Ignition delay of distillate fuels is measured by heating a block to an elevated temperature and injecting samples into a cavity in the block as it cools. The time between each injection and ignition of the fuel is measured. This measurement of ignition delay is used to determine the cetane number of the distillate fuel.
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: October 29, 1985
    Assignee: Mobil Oil Corporation
    Inventors: Chaya Venkat, Dennis E. Walsh
  • Patent number: 4494961
    Abstract: The invention provides a method for increasing the cetane number of a low hydrogen content, highly aromatic distillate fuel by subjecting it to catalytic partial oxidation. Catalysts employed include transition metal oxides alone or in conjuction with alkali metal or alkaline earth metal compounds. Partial oxidation in accordance with the method of this invention not only results in cetane number improvement, but also allows a higher concentration of aromatic substituents in the fuel blend.
    Type: Grant
    Filed: June 14, 1983
    Date of Patent: January 22, 1985
    Assignee: Mobil Oil Corporation
    Inventors: Chaya Venkat, Dennis E. Walsh