Patents by Inventor Dat S. Trieu

Dat S. Trieu 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).

  • Two-stage crystallization of nitrilotriacetonitrile from a hot solution
    Patent number: 4485049
    Abstract: A process is disclosed for producing crystalline nitrilotriacetonitrile from a solution of nitrilotriacetonitrile and water in excess of 95.degree. C., comprising:a. cooling the nitrilotriacetonitrile-water solution in a first stage to the range of about 70.degree. C. to about 90.degree. C., preferably from about 80.degree. C. to about 90.degree. C., and more preferably about 85.degree. C., to produce a nitrilotriacetonitrile water slurry; andb. further cooling the nitrilotriacetonitrile-water slurry in a second stage to below about 35.degree. C., carried out either continuously or in a batch process. Cooling in the first stage is preferably accomplished by recycling cooled nitrilotriacetonitrile-water slurry from the second stage. Cooling in the second stage is preferably accomplished by vacuum cooling.
    Type: Grant
    Filed: January 3, 1983
    Date of Patent: November 27, 1984
    Assignee: Monsanto Company
    Inventors: Kent P. Lannert, Chung Y. Shen, Dat S. Trieu