Patents by Inventor Didier Demay

Didier Demay 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: 6540921
    Abstract: Process for the on-site purification of an aqueous hydrogen peroxide solution, in which the solution is made to pass through a resin bed capable, at least partially, of adsorbing or absorbing the impurities present in the solution. The hydrogen peroxide solution is injected into the resin bed and passes through the latter at an approximately linear velocity preferably of between 10 m/h and 50 m/h and more preferably between 10 m/h and 20 m/h, while the resin bed is kept substantially compacted for at least 50% of the time during which the solution is being purified by coming into contact with the said resin.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: April 1, 2003
    Assignee: L'Air Liquide Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Christine Devos, Didier Demay, Hervé Dulphy
  • Patent number: 6296829
    Abstract: Process for purifying an aqueous hydrogen peroxide solution containing impurities, some of which are in ionic form, in which the said aqueous solution is purified by passing it through at least one first resin of anionic type in order to remove at least some anionic impurities, and then through a second resin of cationic type in order to remove at least some of the cationic impurities, or vice versa, characterized in that at least a first and a second bed of a first resin of anionic type are arranged in parallel, in that the aqueous solution is directed alternately onto the said first or the said second bed, and in that changeover from the first bed to the second bed (or vice versa) is carried out when the said first [lacuna] is at least partially saturated with at least one of the anions constituting the anionic impurities.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: October 2, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Christine Devos, Didier Demay
  • Patent number: 6214225
    Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes successively passing a solution to be purified through at least two beds of cation-exchange adsorbents (CEA) and two beds of anion-exchange adsorbents (AEA) according to the sequence: AEA→CEA→AEA→CEA Also provided is a plant for the implementation of the inventive process.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: April 10, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Henry Ledon, Martine Carre, Didier DeMay, Christine DeVos, Serge Jeanin
  • Patent number: 6187189
    Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes passing a solution to be purified successively through at least one bed of anion-exchange adsorbents (AEA) and at least one bed of cation-exchange adsorbents (CEA). A non-zero proportion of the solution exiting from one of the beds is recycled to a point upstream of the one bed or upstream of a preceding bed or upstream of the first bed of the first of the at least one sequence. Also provided is a plant for the implementation of the inventive process.
    Type: Grant
    Filed: March 25, 1999
    Date of Patent: February 13, 2001
    Assignee: L'air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Henry Ledon, Christine Devos, Didier Demay
  • Patent number: 5961947
    Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes successively passing a solution to be purified through at least two beds of cation-exchange adsorbents (CEA) and two beds of anion-exchange adsorbents (AEA) according to the sequence:AEA .fwdarw. CEA .fwdarw. AEA .fwdarw. CEAAlso provided is a plant for the implementation of the inventive process.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: October 5, 1999
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Henry Ledon, Martine Carre, Didier Demay, Christine Devos, Serge Jeanin
  • Patent number: 5928621
    Abstract: Provided is a process for the preparation of an ultrapure hydrogen peroxide solution. The process comprises at least one sequence which includes passing a solution to be purified successively through at least one bed of anion-exchange adsorbents (AEA) and at least one bed of cation-exchange adsorbents (CEA). A non-zero proportion of the solution exiting from one of the beds is recycled to a point upstream of the one bed or upstream of a preceding bed or upstream of the first bed of the first of the at least one sequence. Also provided is a plant for the implementation of the inventive process.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: July 27, 1999
    Assignee: L'Air Liquide, Societe Anonyme Pour L'Etude et L'Exploitation des Procedes Georges Claude
    Inventors: Henry Ledon, Christine Devos, Didier Demay