Patents by Inventor Theodorus F. M. de Graaf

Theodorus F. M. de Graaf 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: 4386207
    Abstract: An improved process for the preparation of pyridines and/or hydrogened pyridines that have been substituted with a hydrocarbon group at one or more carbon atoms. .gamma.-cyanoketone, in a gaseous phase and in the presence of hydrogen, is passed over a first catalyst in a reaction zone to form a reaction mixture containing substituted pyridines and/or hydrogenated pyridines and hydrogen. A hydrogen-containing gas is separated from the reaction mixture and, prior to being recycled, is subjected to a two-step catalytic treatment. In the first catalytic treatment step, the hydrogen-containing gas is passed over an iron, nickel, cobalt, or platinum-containing catalyst at a temperature of between about 250.degree. and 550.degree. C. In the second catalytic treatment step, the hydrogen-containing gas is passed over an iron, nickel, or cobalt catalyst at a temperature of between about 550.degree. and 800.degree. C.
    Type: Grant
    Filed: November 13, 1981
    Date of Patent: May 31, 1983
    Assignee: Stamicarbon B.V.
    Inventors: Theodorus F. M. de Graaf, Charles H. Geersheuvels
  • Patent number: 4383124
    Abstract: An improved process for the dehydrogenation of alcohols, to produce aldehydes therefrom, using a copper-containing catalyst, is described wherein the alcohol is introduced in the gas phase initially in admixture with an inert gas only, and after an initial reaction period the alcohol is continued to be introduced, in the gas phase, in an admixture with an inert gas together with a minor amount of hydrogen. As a result, prolonged catalyst activity with retained selectivity is achieved.
    Type: Grant
    Filed: March 27, 1981
    Date of Patent: May 10, 1983
    Assignee: Stamicarbon, B.V.
    Inventors: Theodorus F. M. de Graaf, Hubertus J. A. Delahaye
  • Patent number: 4339604
    Abstract: An improved method for the preparation of cyclohexanol and/or cyclohexanone from benzene. Cyclohexanol and/or cyclohexanone is prepared by the steps of hydrogenating benzene to form a hydrogenation reaction mixture containing cyclohexene, unreacted benzene, and by-product cyclohexane, hydrating cyclohexene thus obtained to form a hydration reaction mixture containing cyclohexanol, unreacted benzene and by-product cyclohexane and/or oxidating this cyclohexene to form an oxidation reaction mixture containing cyclohexanone, unreacted benzene and by-product cyclohexane, recovering from said hydration reaction mixture the cyclohexanol product and/or from said oxidation reaction mixture the cyclohexanone product, and an organic phase containing unreacted benzene and by-product cyclohexane, and recycling unconverted benzene to the benzene hydrogenation step.
    Type: Grant
    Filed: October 30, 1980
    Date of Patent: July 13, 1982
    Assignee: Stamicarbon, B.V.
    Inventors: Paul C. van Geem, Theodorus F. M. de Graaf, Dirk Knol, Otto G. Plantema
  • Patent number: 4308413
    Abstract: A method for the preparation of an alkyl benzene by dehydrogenation of the corresponding alkenyl cyclohexene in the presence of carrier borne noble metal catalyst wherein a non-acidic material is used as the catalyst carrier and the reaction is initially conducted at a lower temperature for a period of time and subsequently at a higher temperature.
    Type: Grant
    Filed: July 7, 1980
    Date of Patent: December 29, 1981
    Assignee: Stamicarbon, B.V.
    Inventors: Theodorus F. M. de Graaf, Ludovicus H. W. Janssen