Patents by Inventor Jan Hook

Jan Hook 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).

  • Process for bleaching of lignocellulose-containing pulp using a chelating agent prior to a peroxide-ozone-peroxide sequence
    Patent number: 5658429
    Abstract: A process for delignification and bleaching of chemically digested lignocellulose-containing pulp, where the pulp is treated with a complexing agent at a pH between 3.1 and 9.0, whereupon the pulp is bleached with ozone. The initial treatment with a complexing agent removes the ions of certain metals detrimental to the subsequent ozone bleaching, while retaining in the pulp the desirable ions, primarily of alkaline earth metals. Thereby, the selectivity in the delignification is increased and the strength of the pulp maintained. The pulp can be bleached with peroxide before the ozone step and/or after the treatment according to the invention, to obtain the desired final brightness and completely avoid formation and discharge of chlorinated organic compounds.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: August 19, 1997
    Assignee: Eka Nobel AB
    Inventors: Lennart Andersson, Jiri Basta, Lillemor Holtinger, Jan Hook