Patents by Inventor Johannes Pieter Vrijenhoef

Johannes Pieter Vrijenhoef 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).

  • Crystallisation of materials from aqueous solutions
    Patent number: 7127913
    Abstract: The invention is directed to a process for recovering a crystalline material from an aqueous solution, which solution also contains organic contaminants, in which process the material is crystallised from the aqueous solution by freeze crystallising at a eutectic freezing point of the solution.
    Type: Grant
    Filed: October 20, 2000
    Date of Patent: October 31, 2006
    Assignees: Technische Universiteit Delft, Kemira GrowHow Oyj
    Inventors: Geert-Jan Witkamp, Johannes Pieter Vrijenhoef, Johannes de Graauw, Frank van der Ham