Patents by Inventor Lambertus H. W. M. Van Lieshout

Lambertus H. W. M. Van Lieshout 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 to continuously prepare an aqueous mixture of &egr;-caprolactam and &egr;-caprolactam precursors
    Patent number: 6452002
    Abstract: Process for preparing an aqueous mixture of &egr;-caprolactam and 6-aminocaproic acid and/or 6-aminocaproamide which involves, as the reductive amination step, contacting 5-formylvaleric acid and/or an alkyl 5-formylvalerate in water as solvent with hydrogen and an excess of ammonia in the presence of a ruthenium on carrier, as a catalyst, wherein the carrier is titanium oxide, zirconium oxide, graphite or carbon and the catalyst also contains at least one of the metals of group 8-11, or a compound of these metals. The aqueous mixture can be used to prepare &egr;-caprolactam.
    Type: Grant
    Filed: March 1, 2001
    Date of Patent: September 17, 2002
    Assignees: DSM N.V., E.I. du Pont de Nemours and Company
    Inventors: Robert Pestman, Lambertus H. W. M. Van Lieshout
  • Process to continuously prepare an aqueous mixture of epsilon-caprolactam and epsilon-caprolactam precursors
    Publication number: 20020007058
    Abstract: Process for preparing an aqueous mixture of &egr;-caprolactam and 6-aminocaproic acid and/or 6-aminocaproamide which involves, as the reductive amination step, contacting 5-formylvaleric acid and/or an alkyl 5-formylvalerate in water as solvent with hydrogen and an excess of ammonia in the presence of a ruthenium on carrier, as a catalyst, wherein the carrier is titanium oxide, zirconium oxide, graphite or carbon and the catalyst also contains at least one of the metals of group 8-11, or a compound of these metals. The aqueous mixture can be used to prepare &egr;-caprolactam.
    Type: Application
    Filed: March 1, 2001
    Publication date: January 17, 2002
    Inventors: Robert Pestman, Lambertus H.W.M. Van Lieshout
  • Process for preparing hydroxylammonium salts
    Patent number: 6221328
    Abstract: The invention relates to a process for preparing a hydroxylammonium salt through catalytic reduction of nitrate ions in an acid medium in the presence of a palladium and/or platinum catalyst on a carrier in which at least 0.00025 mmol halogen ions are present per m2 of palladium and/or platinum area.
    Type: Grant
    Filed: April 28, 1999
    Date of Patent: April 24, 2001
    Assignee: DSM N.V.
    Inventors: Lambertus H. W. M. Van Lieshout, Peter A. C. Schevelier, Leonardus Lefferts
  • Process for the preparation of hydroxylammonium salts
    Patent number: 5792439
    Abstract: The invention relates to a process for the preparation of a hydroxylammonium salt through catalytic reduction of nitrate ions in an acid medium, in the presence of an activated catalyst, which catalyst comprises carrier particles with a plurality of metal particles containing palladium and platinum, the relative concentrations of the palladium and the platinum in each metal particle being substantially the same. In particular, the distribution of platinum concentrations among different metal particles has a standard deviation of less than 4% absolute.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: August 11, 1998
    Assignee: DSM N.V.
    Inventors: Lambertus H.W.M. van Lieshout, Peter A.C. Schevelier, Leonardus Lefferts