Patents by Inventor Purnesh Seegopaul

Purnesh Seegopaul 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).

  • Publication number: 20090324470
    Abstract: The present invention relates to a process for producing an activated perovskite-based washcoat formulation suitable for reduction of carbon monoxide, volatile organic compounds, particulate matter, and nitrogen oxides emissions from an exhaust gas stream. The process includes the steps of high energy ball milling a fully synthesized perovskite structure to provide an activated nanocrystalline perovskite powder of a given surface area; mixing the activated nanocrystalline perovskite powder with dispersing media and grinding the mixture; removing partially or totally the dispersing media to obtain an activated perovskite-based catalyst washcoat formulation wherein the activated perovskite in the formulation has a specific surface area greater than that of the activated nanocrystalline perovskite powder. The process may further include a step of applying the formulation on a substrate to obtain a catalytic converter.
    Type: Application
    Filed: June 12, 2007
    Publication date: December 31, 2009
    Inventors: Houshang Alamdari, Mahbod Bassir, Purnesh Seegopaul, André Van Neste
  • Patent number: 6852303
    Abstract: A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300° C. to maximum temperature 850° C., a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750° C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction and the water gas shift reaction.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: February 8, 2005
    Assignee: N.V. Union Miniere S.A. et al.
    Inventors: Purnesh Seegopaul, Lin Gao
  • Publication number: 20040062710
    Abstract: A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300° C. to maximum temperature 850° C., a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750° C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction and the water gas shift reaction.
    Type: Application
    Filed: September 30, 2003
    Publication date: April 1, 2004
    Applicant: N.V. Union Miniere S.A. et al.
    Inventors: Purnesh Seegopaul, Lin Gao
  • Patent number: 6524366
    Abstract: Tungsten carbide is formed from a tungsten material which is preferably tungsten carbide scrap. If scrap material is used, this is oxidized and acid leached to remove impurities and any binder material. This is then dissolved in a solution of sodium hydroxide and spray dried to form a precursor compound. A carbon compound such as citric acid can be added to the solution prior to spray drying to provide a carbon source for the tungsten carbide. The powder formed from the spray dried solution is calcined and carburized to form tungsten carbide.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: February 25, 2003
    Assignee: N.V. Union Miniere S.A.
    Inventors: Purnesh Seegopaul, Lin Gao
  • Publication number: 20020172641
    Abstract: A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300° C. to maximum temperature 850° C., a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750° C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction and the water gas shift reaction.
    Type: Application
    Filed: March 26, 2001
    Publication date: November 21, 2002
    Applicant: N.V. Union Miniere S.A.
    Inventors: Purnesh Seegopaul, Lin Gao
  • Patent number: 6207609
    Abstract: A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300° C. to maximum temperature 850° C., a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750° C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: March 27, 2001
    Assignee: N.V. Union Miniere S.A.
    Inventors: Lin Gao, Purnesh Seegopaul
  • Patent number: 5919428
    Abstract: Nanograined tungsten carbide particles are formed by a controlled, simultaneous reduction carburization reaction wherein the kinetics of the carburization and reduction reactions are controlled to permit simultaneous reduction and carburization. The kinetics are controlled by reacting a reduction carburization gas mixture, preferably hydrogen and carbon monoxide by slowly increasing the reaction temperature by controlling the rate of temperature increase. Preferably, the reaction temperature will be increased less than 25.degree. C. per minute, preferably about 1-2 degrees per minute, which prevents the formation of stable, undesirable species such as W.sub.2 C, which in turn interferes with the reaction efficiency.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: July 6, 1999
    Assignee: Nanodyne Incorporated
    Inventors: Lin Gao, Bernard Kear, Purnesh Seegopaul
  • Patent number: 5885372
    Abstract: Grain growth inhibitors including vanadium carbide, chromium carbide, tantalum carbide, and niobium carbide are incorporated into a cobalt/tungsten carbide matrix during the formation of the cobalt/tungsten carbide matrix. A precursor powder is formed by combining in solution a cobalt composition, a tungsten composition and a grain growth inhibiting metal composition, which is then spray dried. The precursor compound is then carburized in carbon monoxide and carbon dioxide to form cobalt/tungsten carbide matrix. This is then further carburized in a hydrocarbon hydrogen gas at an elevated temperature to cause the grain growth inhibiting metal present to form the carbide. The second carburizing step is conducted with a carburizing gas having a carbon activity greater than about 2 for a relatively short period of time at 900.degree. C. to 1000.degree. C.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: March 23, 1999
    Assignee: Nanodyne Incorporated
    Inventor: Purnesh Seegopaul
  • Patent number: 5869019
    Abstract: In order to eliminate the oxygen sensitivity of chromium carbide and vanadium carbide particles, vanadium carbide and chromium carbide particles are formed by carburizing a precursor compound at a elevated reaction temperature of about 950.degree. C. Initially, the precursor compound is heated in an inert nitrogen-containing gas to the reaction temperature. Once the reaction temperature is achieved, hydrogen and a carbon-containing gas such as methane or ethylene are used to conduct the carbonization. After the carbonization has been completed, the carbonizing gas is then replaced with an inert nitrogen-containing gas and the product allowed to cool down. The carbonization cycle is adjusted so that the oxygen level is kept to less than 0.35%, while the nitrogen level is kept at about 2%. Powders produced from this process show minimal or no oxygen pickup when exposed to ambient air.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: February 9, 1999
    Assignee: Nanodyne Incorporated
    Inventor: Purnesh Seegopaul
  • Patent number: 5728197
    Abstract: Tungsten carbide cobalt and tungsten-containing materials are recycled using a single high-temperature oxidation with standard dilution chemistry. The scrap material is ground, oxidized, and subjected to an acid digestion, preferably in hydrochloric acid. This causes the cobalt to form cobalt chloride while the tungsten remains insoluble. The pH is then increased to about 7.0 which causes the cobalt chloride to form cobalt hydroxide which precipitates out of solution. The cobalt and tungsten are separated and dissolved in a high-pH ammonia solution which can then be spray dried to form a precursor powder for subsequent carburization to form tungsten carbide-cobalt powders.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: March 17, 1998
    Assignee: Nanodyne Incorporated
    Inventors: Purnesh Seegopaul, Li Wu
  • Patent number: 5613998
    Abstract: Tungsten carbide and/or tungsten can be recycled by oxidizing the tungsten composition at a temperature greater than 700.degree. C. to form a water insoluble tungsten trioxide. This is then reduced to form tungsten dioxide. The tungsten dioxide is subjected to a low temperature oxidation which forms monoclinic tungsten trioxide. The monoclinic tungsten trioxide is then dissolved in ammonia to form ammonium tungstate. If present, the binder metal such as cobalt is converted into the soluble ammine complex. This can be spray dried and carburized to form tungsten carbide. If the form composition includes cobalt or other binder metal, the ratio of cobalt to tungsten can be adjusted by adding cobalt salts or ammonium metatungstate to the aqueous solution prior to spray drying to form a precursor composition. This is uniquely suitable for forming a cobalt tungsten carbide composition.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: March 25, 1997
    Assignee: Nanodyne Incorporated
    Inventors: Purnesh Seegopaul, Li Wu
  • Patent number: 5230462
    Abstract: A method of bonding a sputtering target to a backing member or plate for subsequent use in a sputtering operation. A target and a backing plate are first provided and one face of each of the target and backing plate are wetted with solder. The target and backing plate are then submerged in a solder bath, and the wetted faces of the target and backing plate are pressed into contact. The target and backing plate are then removed from the solder bath and while maintaining them pressed together, the solder interface therebetween is cooled directionally by causing cooling to occur from the center of the solder interface radially outwardly toward the periphery. The lowermost of the target and backing plate is provided with a circumferential lip adjacent the periphery of the solder interface.
    Type: Grant
    Filed: July 8, 1992
    Date of Patent: July 27, 1993
    Assignee: Materials Research Corporation
    Inventors: Milan Vascak, Anthony Sica, Purnesh Seegopaul