Patents by Inventor Takayasu Niwa

Takayasu Niwa 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).

  • Regeneration of catalysts by burning in the presence of alcohols
    Patent number: 5071802
    Abstract: Carbonaceous materials deposited on solid catalysts and produced, for example, in Beckmann rearrangement in a gaseous phase are burned off by effecting the treatment in the presence of alcohols such as methanol or ethanol together with molecular oxygen-containing gas in order to regenerate the catalyst activity.
    Type: Grant
    Filed: March 7, 1990
    Date of Patent: December 10, 1991
    Assignee: Sumitomo Chemical Co., Ltd.
    Inventors: Shinkichi Shimizu, Takayasu Niwa, Nobuyuki Abe, Masanori Doba, Akira Iguchi, Hiroshi Ichihashi, Masaru Kitamura
  • Material for recovering uranium and method for recovering a uranium solution of high purity and high concentration, using the same
    Patent number: 4199470
    Abstract: Uranium is recovered from its solution through contact with a uranium-recovering material of higher resistance to water and higher mechanical strength comprising a weakly basic anion exchange resin having pyridine nuclei at its main chain or side chain, and a crossed-linked polymer structure with a high uranium selectivity at a high uranium-adsorbing speed.
    Type: Grant
    Filed: May 5, 1978
    Date of Patent: April 22, 1980
    Assignee: Koei Chemical Co., Ltd.
    Inventors: Shinichi Yasuda, Takayasu Niwa, Takayuki Kurohara