Patents by Inventor Ryozo Hamana

Ryozo Hamana 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: 6388154
    Abstract: A process for producing styrene by oxidative dehydrogentation of ethylbenzene, wherein the dehydrogenation of ethylbenzene is conducted through at least the following steps (1) to (3), whereby styrene can be produced in a high yield by controlling the lowering of the selectivity of an oxidation catalyst in hydrogen oxidation by removing an alkaline substance contained in the reaction mixture to be fed to step (2) beforehand: step (1): a step of dehydrogenating ethylbenzene in the presence of a dehydrogenation catalyst to obtain a reaction mixture containing styrene and hydrogen; step (2): a step of bringing the reaction mixture into contact with an oxidation catalyst to selectively oxidize the hydrogen contained in the mixture, thereby forming water; step (3): a step of bringing the oxidized mixture into contact with a dehydrogenation catalyst to dehydrogenate the unreacted ethylbenzene contained in the mixture, thereby obtaining styrene.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: May 14, 2002
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Ryozo Hamana, Shohei Suzuki, Syuji Obayashi, Makoto Takiguchi, Hisashi Fujita
  • Patent number: 5023383
    Abstract: Aromatic alcohol is produced by reducing aromatic hydroperoxide with hydrogen in a liquid phase, using a Pt catalyst solely or a catalyst containing Pt and at least one element selected from the group consisting Pb, Sn, Cu, As, Sb, In, Se and Bi in a fixed bed reactor.
    Type: Grant
    Filed: January 3, 1990
    Date of Patent: June 11, 1991
    Assignee: Mitsubishi Petrochemical Co., Ltd.
    Inventors: Masashi Inaba, Ryozo Hamana, Hideyuki Hase, Tatsuro Ashizawa
  • Patent number: 4605742
    Abstract: A process for the production of piperidine by catalytic hydrogenation of furfurylamine and/or tetrahydrofurfurylamine in the presence of a hydrogenation catalyst by flowing hydrogen gas into a reaction zone, wherein the starting material is introduced into a liquid phase in the reaction zone, the liquid phase being maintained at a constant temperature, and the reaction product is withdrawn from the reaction zone in a gaseous form together with excess hydrogen gas.
    Type: Grant
    Filed: February 7, 1985
    Date of Patent: August 12, 1986
    Assignee: Mitsubishi Petrochemical Co., Ltd.
    Inventors: Shoichiro Mori, Tadamichi Aoki, Ryozo Hamana, Yutaka Nomura
  • Patent number: 4598159
    Abstract: A process for producing furfurylamine and/or tetrahydrofurfurylamine in a high yield is disclosed, which comprises subjecting a mixture of furfural and a primary amine to a liquid-phase catalytic hydrogenation using a hydrogenation catalyst in the presence of ammonia, wherein the primary amine is furfurylamine and/or tetrahydrofurfurylamine and the hydrogenation catalyst is selected from the group consisting of cobalt-based catalysts and nickel-based catalysts.
    Type: Grant
    Filed: December 27, 1984
    Date of Patent: July 1, 1986
    Assignee: Mitsubishi Petrochemical Co., Ltd.
    Inventors: Tadashi Ayusawa, Shoichiro Mori, Tadamichi Aoki, Ryozo Hamana
  • Patent number: 4544749
    Abstract: Catalytic hydrogenation of furfurylamine or tetrahydrofurfurylamine in the presence of a cobalt-based catalyst into piperidine can be industrially carried out in an organic solvent, wherein addition of ammonia is not needed. It has been believed heretofore that the presence of ammonia in the hydrogenation is essential in such catalytic hydrogenation.
    Type: Grant
    Filed: February 24, 1984
    Date of Patent: October 1, 1985
    Assignee: Mitsubishi Petrochemical Company Limited
    Inventors: Tadashi Ayusawa, Tadamichi Aoki, Ryozo Hamana