Patents by Inventor Nak-Mo Choi

Nak-Mo Choi 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: 7427579
    Abstract: The present invention relates to a hydrogenation catalyst represented by the following formula 1, a method for the preparation thereof, and a method for preparing gamma-butyrolactone using this catalyst. The method for preparing gamma-butyrolactone from maleic anhydride using the catalyst of the invention prepared by stabilizing the precursor particles of copper oxide, zinc oxide, and manganese oxide with a silica exhibits high selectivity, high yield, and high productivity under the operation conditions of a low molar ratio of hydrogen with regard to the reactants, and enables the preparation of gamma-butyrolactone from maleic anhydride with long-term stability without requiring frequent re-activation of the catalyst: Formula (I) CuO(a)ZnO(b)MnO2(c)SiO2(d) wherein a, b, c, and d are represented on the basis of weight, wherein a is 20 to 90, b is 0.01 to 10, c is 0.01 to 5, and d is 5 to 50.
    Type: Grant
    Filed: April 18, 2003
    Date of Patent: September 23, 2008
    Assignees: Ackyung Petrochemical Co., Ltd., Korea Research Institute of Chemical Technology
    Inventors: Jung-Ho Lee, Hyung-Rok Kim, Yo-Han Han, Suk-Jong Jeong, Nak-Mo Choi, Hang-Soo Woo, In-Ki Kim
  • Publication number: 20050240033
    Abstract: The present invention relates to a hydrogenation catalyst represented by the following formula 1, a method for the preparation thereof, and a method for preparing gamma-butyrolactone using this catalyst. The method for preparing gamma-butyrolactone from maleic anhydride using the catalyst of the invention prepared by stabilizing the precursor particles of copper oxide, zinc oxide, and manganese oxide with a silica exhibits high selectivity, high yield, and high productivity under the operation conditions of a low molar ratio of hydrogen with regard to the reactants, and enables the preparation of gamma-butyrolactone from maleic anhydride with long-term stability without requiring frequent re-activation of the catalyst: Formula (1) CuO(a)ZnO(b)MnO2(c)SiO2(d) wherein a, b, c, and d are represented on the basis of weight, wherein a is 20 to 90, b is 0.01 to 10, c is 0.01 to 5, and d is 5 to 50.
    Type: Application
    Filed: April 18, 2003
    Publication date: October 27, 2005
    Inventors: Jung-Ho Lee, Hyung-Rok Kim, Yo-Han Han, Suk-Jong Jeong, Nak-Mo Choi, Hang-Soo Woo, In-Ki Kim