Patents by Inventor Ralf Grimmer

Ralf Grimmer 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).

  • Method for delignifying and bleaching pulp
    Patent number: 10006169
    Abstract: Process for the delignification and bleaching of pulp, comprising a first bleaching stage with hydrogen peroxide in the presence of a molybdate or tungstate in an acidic aqueous mixture; subsequent to the first bleaching stage, a second bleaching stage with hydrogen peroxide in an alkaline aqueous mixture; and, subsequent to the second bleaching stage, a third bleaching stage with hydrogen peroxide in the presence of a molybdate or tungstate in an acidic aqueous mixture.
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: June 26, 2018
    Assignee: Evonik Degussa GmbH
    Inventors: Thomas Dietz, Bernd Hopf, Ralf Grimmer, Sigrid Wegmann, Verena Illhardt
  • METHOD FOR DELIGNIFYING AND BLEACHING PULP
    Publication number: 20160298294
    Abstract: Process for delignifying and bleaching pulp Process for the delignification and bleaching of pulp, comprising a first bleaching stage with hydrogen peroxide in the presence of a molybdate or tungstate in an acidic aqueous mixture; subsequent to the first bleaching stage, a second bleaching stage with hydrogen peroxide in an alkaline aqueous mixture; and, subsequent to the second bleaching stage, a third bleaching stage with hydrogen peroxide in the presence of a molybdate or tungstate in an acidic aqueous mixture.
    Type: Application
    Filed: October 15, 2014
    Publication date: October 13, 2016
    Applicant: Evonik Degussa GmbH
    Inventors: Thomas DIETZ, Bernd HOPF, Ralf GRIMMER, Sigrid WEGMANN, Verena ILLHARDT
  • METHOD FOR RECOVERY OF MOLYBDATE IN A MOLYBDATE-CATALYSED DELIGNIFICATION OF PULP WITH HYDROGEN PEROXIDE
    Publication number: 20150007951
    Abstract: In a delignification of pulp with hydrogen peroxide catalyzed by molybdate, molybdate can be recovered by contacting the molybdate-containing aqueous solution at a pH in the range from 2 to 7 with a carrier material comprising a sheet silicate been ion-exchanged with a quaternary ammonium salt and subsequent flotation without a surfactant having to be added for flotation.
    Type: Application
    Filed: December 19, 2012
    Publication date: January 8, 2015
    Applicant: Evonik Industries AG
    Inventors: Thomas Dietz, Bernd Hopf, Ralf Grimmer
  • Flotation process for mechanical pulp using a surface active agent
    Patent number: 5554258
    Abstract: An improved process for bleaching pulps is disclosed in which the unbleached pulp is subject to flotation before bleaching and, if necessary, the circulating water is also purified of interfering compounds by flotation.
    Type: Grant
    Filed: May 5, 1994
    Date of Patent: September 10, 1996
    Assignee: Degussa Aktiengesellschaft
    Inventors: Hans U. Suess, Norbert Nimmerfroh, Ralf Grimmer