Patents by Inventor Colin D. Chriswell

Colin D. Chriswell 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: 5505746
    Abstract: Methods and compositions are provided for treating coal to reduce the emissions of sulphur dioxide and hydrogen chloride gases upon combustion. In the subject method, coal is washed with a calcium anion wash solution, such as calcium hydroxide solution, and then separated from the wash solution. The treated coal exhibits reduced emissions of both sulphur dioxide and hydrogen chloride gas on combustion as compared with untreated coal.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: April 9, 1996
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Colin D. Chriswell, Josh A. O'Donnell
  • Patent number: 5478452
    Abstract: Methods and apparatus for in sire isolation of volatile organic compounds from groundwater using electrolytically-generated purge gas are disclosed. One preferred method includes electrolytically generating a purge gas from the ground water, passing the purge gas through the groundwater (in situ) to purge volatile organic compounds from groundwater, collecting the purge gas along with the purged volatile organic compounds, and detecting (in situ) the presence and/or amount of purged volatile organic compounds in the purge gas. One preferred apparatus includes a generally cylindrical cell incorporating the necessary electrodes, one or more ionization sources and detectors.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: December 26, 1995
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Colin D. Chriswell, John J. Richard
  • Patent number: 5181428
    Abstract: A device for testing soil samples is comprised of a closed container having an interior compartment with upper and lower portions. A valve is provided for introducing into the closed container a liquid having the general properties of butane, and a second valve is provided in the container for allowing gas in the closed container to exit therefrom. A soil sample filter container is suspended within the container above the bottom portion thereof. A condensation element is mounted in the closed container and positioned above the filter container to cause gas evaporating from the liquid in the container to liquefy as condensate on the condensation element, whereupon the condensate drips into the filter container and leaches through a soil sample therein, and then collects as a liquid in the bottom portion of the closed container. This permits a hydrocarbon residue to be left in the bottom portion of the container after the outlet valve has been opened to permit the liquid to evaporate.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: January 26, 1993
    Assignee: Iowa State University Research Foundation, Inc.
    Inventor: Colin D. Chriswell
  • Patent number: 5024753
    Abstract: An improved material separation system and method utilizing control particles of generally known physical characteristics as tracer particles through the separation process. The control particles are generally the same or similar to the materials being separated and are coated with or bonded to a fluorescing dye. The control particles are mixed with the material to be separated prior to separation. The mixture is imposed with a energy source which excites the fluorescent dye causing fluorescing emission. The fluorescing emission is detected at the output of the separation of the mixture to determine if the separation is operating efficiently and as desired.
    Type: Grant
    Filed: October 3, 1989
    Date of Patent: June 18, 1991
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Colin D. Chriswell, Richard Markuszewski, William H. Buttermore
  • Patent number: 4859212
    Abstract: Pretreatment of coal by devolatization at temperatures ranging from about 420.degree. C. to about 450.degree. C. for from about 10 minutes to about 30 minutes before leaching with molten caustic leads to a significant reduction in carbonate formation, greatly reducing the cost of cleaning coal on a per ton basis.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: August 22, 1989
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Colin D. Chriswell, Surender M. Kaushik, Navin D. Shah, Richard Markuszewski
  • Patent number: 4277635
    Abstract: Relatively dilute aqueous solutions of ethanol are concentrated by passage through a bed of a crystalline silica polymorph, such as silicalite, to adsorb the ethanol with residual dilute feed in contact with the bed, which is displaced by passing concentrated aqueous ethanol through the bed without displacing the adsorbed ethanol. A product concentrate is then obtained by removing the adsorbed ethanol from the bed together with at least a portion of the concentrated aqueous ethanol used as the displacer liquid. This process permits ethanol to be concentrated from dilute fermentation beers, which may contain from 6 to 10% ethanol, to obtain a concentrate product at very low energy cost having an ethanol concentration in excess of 95%, such as a concentration of from 98 to 99.5%.
    Type: Grant
    Filed: June 24, 1980
    Date of Patent: July 7, 1981
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Charles S. Oulman, Colin D. Chriswell