Patents Assigned to University of North Dakota Energy and Environment Research Center Foundation
  • Leonardite char adsorbents
    Patent number: 5254521
    Abstract: A process of preparing lignite (low rank) coal filter material, suitable for use in lieu of more expensive activated carbon filter materials, is disclosed. The process comprises size reducing Leonardite coal material to a suitable filtering effective size, and thereafter heating the size reduced Leonardite preferably to at least 750.degree. C. in the presence of a flow of an inert gas.
    Type: Grant
    Filed: August 3, 1992
    Date of Patent: October 19, 1993
    Assignee: University of North Dakota Energy and Environment Research Center Foundation
    Inventor: Curtis L. Knudson