Patents by Inventor Diwakar Garg

Diwakar Garg 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: 4902535
    Abstract: The invention discloses a coated substrate product comprises of a titanium or titanium alloy substrate, at least one thin interlayer composed of a non-reactive noble metal and a hard outer coating selected from the group comprised of a ceramic, hard metal, a hard metal compound and a diamond-like carbon, wherein at least the non-reactive noble metal interlayer which is immediately adjacent to the titanium or titanium alloy substrate is deposited onto the substrate by means of an electroless plating procedure, and the hard outer coating is deposited onto the non-reactive interlayer(s) by means of known chemical and physical vapor deposition techniques. The invention also discloses a method for making these coated substrate products.
    Type: Grant
    Filed: December 31, 1987
    Date of Patent: February 20, 1990
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Carl F. Mueller, Leslie E. Schaffer, Paul N. Dyer
  • Patent number: 4873152
    Abstract: "A coated substrate product is described wherein the outer coating on the substrate is comprised of a chemically vapor deposited and heat treated mixture of tungsten and tungsten carbide. The tungsten carbide phase consists of W.sub.2 C or W.sub.3 C or a mixture of W.sub.2 C and W.sub.3 C. During the heat treating, the coated substrate is heated to the deposition temperature or not substantially above the deposition temperature in a non-reactive atmosphere. The heat treating temperature is sufficient to confer a desired improvement in erosive and abrasive wear resistance in the outer coating but does not result in substantial degradation of the mechanical properties of the substrate or in formation of undesirable inter-metallic layers".
    Type: Grant
    Filed: February 17, 1988
    Date of Patent: October 10, 1989
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Paul N. Dyer, Duane Dimos
  • Patent number: 4855188
    Abstract: A highly erosive and abrasive wear resistant composite coating system is described in which an intermediate layer of substantially pure tungsten is deposited on a substrate. An outer layer is then deposited comprised of a mixture of tungsten and tungsten carbide, with the tungsten carbide consisting of W.sub.2 C, W.sub.3 C or a mixture of both. The thickness of the intermediate layer is sufficient to confer substantial erosive and abrasive wear resistance characteristics on the composite coating system. The ratio of the thickness of the intermediate layer to the thickness of the outer layer is controlled and is at least above 0.30 in the cases of W+W.sub.3 C, W+W.sub.2 C+W.sub.3 C and W+W.sub.2 C coatings.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: August 8, 1989
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Paul N. Dyer, Leslie E. Schaffer, Ernest L. Wrecsics, Duane Dimos, Carl F. Mueller
  • Patent number: 4695369
    Abstract: A process for converting heavy petroleum feedstocks to distillate products with reduced metals and asphaltene content by reaction with hydrogen in the presence of at least two metal catalysts, one a known hydrogenation catalyst and the other either zinc, iron or copper.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: September 22, 1987
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Edwin N. Givens, Frank K. Schweighardt
  • Patent number: 4627913
    Abstract: A process for the solvent refining of coal to distillable, pentane soluble products using a dephenolated and denitrogenated recycle solvent and a recycled, pentane-insoluble, solvent-refined coal material, which process provides enhanced oil-make in the conversion of coal.
    Type: Grant
    Filed: January 9, 1985
    Date of Patent: December 9, 1986
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Edwin N. Givens, Frank K. Schweighardt
  • Patent number: 4626342
    Abstract: An improved process for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a solvent comprises using as catalyst a mixture of a 1,2- or 1,4-quinone and an alkaline compound, selected from ammonium, alkali metal, and alkaline earth metal oxides, hydroxides or salts of weak acids.
    Type: Grant
    Filed: October 29, 1985
    Date of Patent: December 2, 1986
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Swaminathan Sunder
  • Patent number: 4617106
    Abstract: Improved catalysts for catalytic solvent refining or hydroliquefaction of non-anthracitic coal at elevated temperatures under hydrogen pressure in a hydrogen donor solvent comprise a combination of zinc or copper, or a compound thereof, and a Group VI or non-ferrous Group VIII metal, or a compound thereof.
    Type: Grant
    Filed: July 26, 1985
    Date of Patent: October 14, 1986
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Diwakar Garg
  • Patent number: 4606809
    Abstract: High yields of desired distillate oil are obtained by subjecting heavy oil to catalytic conversion with hydrogen at superatmospheric pressure in a temperature staged process, wherein the oil-catalyst slurry is subjected in the initial stage to a temperature in the range of 780.degree.-825.degree. F. (415.degree.-440.degree. C.) and in a subsequent stage to a temperature which is at least 20.degree. F. higher than that employed in the previous stage, preferably in the range of 800.degree.-860.degree. F. (.about.425.degree.-460.degree. C.).
    Type: Grant
    Filed: July 1, 1985
    Date of Patent: August 19, 1986
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Diwakar Garg
  • Patent number: 4486293
    Abstract: A process is described for the liquefaction of coal in a hydrogen donor solvent in the presence of hydrogen and a co-catalyst combination of iron and a Group VI or Group VIII non-ferrous metal or compounds of the catalysts.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: December 4, 1984
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Diwakar Garg
  • Patent number: 4472263
    Abstract: A process is disclosed for the solvent refining of non-anthracitic coal at elevated temperatures and pressure in a hydrogen atmosphere using a hydrocarbon solvent which before being recycled in the solvent refining process is subjected to chemical treatment to extract substantially all nitrogenous and phenolic constituents from the solvent so as to improve the conversion of coal and the production of oil in the solvent refining process. The solvent refining process can be either thermal or catalytic. The extraction of nitrogenous compounds can be performed by acid contact such as hydrogen chloride or fluoride treatment, while phenolic extraction can be performed by caustic contact or contact with a mixture of silica and alumina.
    Type: Grant
    Filed: July 19, 1982
    Date of Patent: September 18, 1984
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Edwin N. Givens, Frank K. Schweighardt
  • Patent number: 4465587
    Abstract: A process is set forth for the solvent extraction and hydroliquefaction of heavy hydrocarbon oils and residua having an API gravity at 60.degree. F. of less than 20.degree. in the presence of a hydrogen atmosphere and a hydrogen donor solvent at elevated temperature and pressure. Alternately, the hydrocarbon feed can be subjected to a vacuum distillation before solvent extraction or the liquefaction can be catalyzed in-situ. The process results in improved oil production and greater denitrogenation desulfurization and demetallization.
    Type: Grant
    Filed: February 28, 1983
    Date of Patent: August 14, 1984
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Robert N. Miller
  • Patent number: 4441983
    Abstract: A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.
    Type: Grant
    Filed: August 19, 1982
    Date of Patent: April 10, 1984
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Diwakar Garg
  • Patent number: 4411766
    Abstract: A process is described for the solvent refining of coal into a gas product, a liquid product and a normally solid dissolved product. Particulate coal and a unique co-catalyst system are suspended in a coal solvent and processed in a coal liquefaction reactor, preferably an ebullated bed reactor. The co-catalyst system comprises a combination of a stoichiometric excess of iron oxide and pyrite which reduce predominantly to active iron sulfide catalysts in the reaction zone. This catalyst system results in increased catalytic activity with attendant improved coal conversion and enhanced oil product distribution as well as reduced sulfide effluent. Iron oxide is used in a stoichiometric excess of that required to react with sulfur indigenous to the feed coal and that produced during reduction of the pyrite catalyst to iron sulfide.
    Type: Grant
    Filed: February 25, 1982
    Date of Patent: October 25, 1983
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Diwakar Garg, Edwin N. Givens
  • Patent number: 4411767
    Abstract: A process is set forth for the integrated liquefaction of coal by the catalytic solvent refining of a feed coal in a first stage to liquid and solid products and the catalytic hydrogenation of the solid product in a second stage to produce additional liquid product. A fresh inexpensive, throw-away catalyst is utilized in the second stage hydrogenation of the solid product and this catalyst is recovered and recycled for catalyst duty in the solvent refining stage without any activation steps performed on the used catalyst prior to its use in the solvent refining of feed coal.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: October 25, 1983
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Diwakar Garg