Patents by Inventor Adolphe M. Douwes

Adolphe M. Douwes 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: 4652678
    Abstract: An improved process for recovering usable components from waste streams containing urea, including a dilute aqueous urea solution, which result from the preparation of particulate urea products. The dilute aqueous urea solution is used to wash a urea containing waste gas stream whereby urea contained in the gas stream is dissolved in the aqueous urea solution. The aqueous urea solution thus obtained is then subjected to a hydrolysis treatment whereby the urea contained therein is hydrolyzed, and the ammonia and carbon dioxide thus formed are separated from the residual liquid stream.
    Type: Grant
    Filed: October 10, 1984
    Date of Patent: March 24, 1987
    Assignee: Stamicarbon B.V.
    Inventor: Adolphe M. Douwes
  • Patent number: 4410503
    Abstract: An improved process for the removal of urea, ammonia, and carbon dioxide from process condensate derived from coupled urea and ammonia syntheses by hydrolysis of urea and desorption of ammonia and carbon dioxide. Process condensate poor with respect to ammonia is treated at a pressure of between about 15 and 42 bar and a temperature of between about 200.degree. C. and 320.degree. C. in a reaction column with steam to form a gas mixture containing ammonia, carbon dioxide, and water vapor, and an aqueous liquid virtually free of urea, ammonia, and carbon dioxide.
    Type: Grant
    Filed: March 1, 1982
    Date of Patent: October 18, 1983
    Assignee: Unie Van Kunst-Mestfabrieken
    Inventors: Petrus J. M. van Nassau, Adolphe M. Douwes