Patents by Inventor Hiroshi Akama

Hiroshi Akama 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: 5681788
    Abstract: A catalyst for the purification of exhaust gas comprises a first coat layer of a palladium-carried activated alumina containing Ce, Zr and La formed on a honeycomb carrier, a second coat layer of an activated alumina containing Ce, Zr and La formed on the first coat layer, and a third coat layer of copper ion-exchanged zeolite powder formed on the second coat layer and efficiently purifies NOx, HC and CO in the exhaust gas under conditions from theoretical air-fuel ratio to excessive oxygen atmosphere.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: October 28, 1997
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Hiroyuki Kanesaka, Hiroshi Akama, Maki Kamikubo
  • Patent number: 5422333
    Abstract: An exhaust gas purification catalyst of high resistance which allows highly effective purification of nitric oxide into nontoxic gas, even for an exhaust gas containing oxygen at a high concentration. A carrier of the catalyst includes crystalline pentasil-type aluminosilicate and supports copper and phosphori, the amount of the phosphori being supported ranges from 0.01% to 6.0% by weight as a conversion to P.sub.2 O.sub.5, and ratio of the phosphorus to the copper, i.e., P/Cu (molar ratio) is in 0<(P/Cu).ltoreq.0.7. A method of reducing and eliminating a nitrogen oxide in an exhaust gas in the presence of a hydrocarbon having a ratio of an overall THC concentration/NO.sub.x concentration of 0.5-50 at a reaction temperature of 200.degree.-800.degree. C. in an oxidative atmosphere.
    Type: Grant
    Filed: August 23, 1993
    Date of Patent: June 6, 1995
    Assignees: Idemitsu Kosan Company Limited, Nissan Motor Co., Ltd.
    Inventors: Yasuhide Kano, Yoshimi Kawashima, Toshiaki Hayasaka, Hiroshi Akama
  • Patent number: 5151256
    Abstract: A coal combustion apparatus having prevented deterioration of a denitration catalyst due to volatile metal compounds contained in exhaust gases is provided, which apparatus comprises a combustion furnace, a denitration means for removing nitrogen oxides in an exhaust gas from the furnace by reducing nitrogen oxide with ammonia, a means for collecting ashes in the gas having left the denitration means and a means for recycling the collected ashes into the furnace, and is characterized in providing an oxygen concentration meter in the flow path of the gas between the furnace and the denitration means and also providing an oxygen concentration-controlling means relative to air fed inside the flow path of the gas from the furnace to the denitration means so as to control the oxygen concentration detected by the oxygen concentration meter to a definite value or higher.
    Type: Grant
    Filed: May 2, 1991
    Date of Patent: September 29, 1992
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Yasuyoshi Kato, Kunihiko Konishi, Nobue Teshima, Toshiaki Matsuda, Hiroshi Akama
  • Patent number: 5087600
    Abstract: A catalyst for denitration by catalytic reduction using ammonia capable of preventing catalyst deterioation due to vapors of heavy metal compounds contained in exhaust gases and having a high strength and a superior resistance to poisons and a process for producing the catalyst are provided, which catalyst comprises TiO.sub.2, oxide(s) of at least one of V, Cu, Fe and Mn and oxide(s) of at least one of Mo, W and Sn, the total of the mol number(s) of the oxide(s) of at least one of Mo, W and Sn falling within a range of 2.times.10.sup.-6 to 20.times.10.sup.-6 mol/m.sup.2 per the unit specific surface of the catalyst, and which process comprises having oxide(s) of at least one of Mo, W and Sn adsorbed and supported onto a composition comprising TiO.sub.2 prepared in advance and oxide(s) of at least one of V, Fe, Cu and Mn so as to give the above-specified total of the mol number(s) of oxide(s) of at least one of Mo, W and Sn.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: February 11, 1992
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Yasuyoshi Kato, Kunihiko Konishi, Hiroshi Akama, Toshiaki Matsuda, Nobue Teshima
  • Patent number: 4966882
    Abstract: A catalyst for denitration by catalytic reduction using ammonia capable of preventing catalyst deterioation due to vapors of heavy metal compounds contained in exhaust gases and having a high strength and a superior resistance to poisons and a process for producing the catalyst are provided, which catalyst comprises TiO.sub.2, oxide(s) of at least one of V, Cu, Fe and Mn and oxide(s) of at least one of Mo, W and Sn, the total of the mol number(s) of the oxide(s) of at least one of Mo, W and Sn falling within a range of 2.times.10.sup.-6 to 20.times.10.sup.-6 mol/m.sup.2 per the unit specific surface of the catalyst, and which process comprises having oxide(s) of at least one of Mo, W and Sn absorbed and supported onto a composition comprising TiO.sub.2 prepared in advance and oxide(s) of at least one of V, Fe, Cu and Mn so as to give the above-specified total of the mol number(s) of oxide(s) of at least one of Mo, W and Sn.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: October 30, 1990
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Yasuyoshi Kato, Kunihiko Konishi, Hiroshi Akama, Toshiaki Matsuda, Nobue Teshima
  • Patent number: 4952548
    Abstract: A catalyst for removing nitrogen oxides contained in exhaust gases, particularly those containing vapor-form catalyst poisons, by catalytic reduction with ammonia, while retaining a high denitration performance for a long time, which catalyst comprises titanium oxide as a first component, molybdenum oxide and/or tungsten oxide as a second component and vanadium oxide and/or sulfate as a third component, the atomic ratio of the respective elements being Ti:Mo and/or W:V=80-96.6:3-15:0.5-5, and the size of the crystallite of the titanium oxide according to Sherrer's equation being in the range of 185 .ANG. to 300 .ANG. in the direction of a plane (101) (interplanar spacing: d=3.52 .ANG.).
    Type: Grant
    Filed: October 18, 1988
    Date of Patent: August 28, 1990
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Yasuyoshi Kato, Kunihiko Konishi, Hiroshi Akama, Toshiaki Matsuda, Nobue Teshima, Fumito Nakajima, Tadaaki Mizoguchi, Masahiro Nitta
  • Patent number: 4798813
    Abstract: A catalyst for removing nitrogen oxides whose activity deterioration due to volatile poisons contained in exhaust gases is prevented and which has a superior endurance, and a process for producing the catalyst are provided, which catalyst comprises a titania having a surface area of 20 m.sup.2 /g or less and a zeolite having 0.01 to 20% by weight of copper supported thereon; having an average pore diameter of 10 .ANG. or less; and having a silica/alumina molar ratio of 10 or more, and which process comprises mixing powder of the zeolite with the titania or its precursor, followed by molding the mixture into a predetermined shape, followed by calcining the resulting material at 800.degree. C. or higher.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: January 17, 1989
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Yasuyoshi Kato, Kunihiko Konishi, Toshiaki Matsuda, Meiji Ito, Taiji Kamiguchi, Nobue Teshima, Hiroshi Akama