Patents by Inventor Cheryl A. Tirtowidjojo

Cheryl A. Tirtowidjojo 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: 6048513
    Abstract: This invention is a method for forming hypohalous acid in a mass transfer device. The method comprises: (1) feeding into the device a stream of caustic solution comprising at least one alkali or alkaline earth metal of a hydroxide, oxide, hypohalite, bicarbonate, or carbonate; (2) feeding a stream comprising halogen gas into the device; (3) reacting at least some of the halogen gas with the caustic solution to form a solution containing hypohalous acid; (4) desorbing the hypohalous acid from the solution and into the stream of halogen gas; and (5) removing the stream of halogen gas from the device. In this method, the mass transfer device comprises a porous rotor which is permeable to the streams, and is rotated about an axis such that the streams flow through the rotor and the stream of caustic solution flows radially outward from the axis.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: April 11, 2000
    Assignee: The Dow Chemical Company
    Inventors: George J. Quarderer, David L. Trent, Erik J. Stewart, Danil Tirtowidjojo, Anil J. Mehta, Cheryl A. Tirtowidjojo
  • Patent number: 5845993
    Abstract: Shear mixing apparatuses and associated methods are disclosed for producing small gas bubbles of a diameter of less than about 0.1 millimeters in a liquid, whereby mass transfer of the gas into the liquid is improved (as compared to the mass transfer achieved by conventional large bubble generators under the same circumstances) in applications benefiting by such improved mass transfer, involving injecting a gas under pressure via one or more orifices into a liquid that is flowing at a velocity sufficient to cause bubbles formed at the orifice(s) to subdivide to the desired small bubble size.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: December 8, 1998
    Assignee: The Dow Chemical Company
    Inventors: Robert Page Shirtum, David L. Trent, Cheryl A. Tirtowidjojo, Paul A. Gillis
  • Patent number: 5532389
    Abstract: A process of preparing alkylene oxides comprises steps of: (1) optionally forming a hypochlorite solution; (2) contacting chlorine with a solution of a hypochlorite below about 60.degree. C., and a pH of less than about 5.5, with sufficient micromixing to achieve a product hypochlorous acid in a yield of at least about 80 percent; (3) separating at least a portion the hypochlorous acid from an aqueous metal chloride solution wherein the solution is sprayed as droplets; (4) distilling the remaining liquid phase; (5) absorbing the hypochlorous acid and dichlorine monoxide in low-chlorides water to produce a low-chlorides aqueous hypochlorous acid solution; (6) contacting the low-chlorides aqueous hypochlorous acid solution with an olefin in a continuous process to form a olefin chlorohydrin; (7) optionally contacting the olefin chlorohydrin with a base to form a alkylene oxide and a salt solution; and (8) optionally separating the alkylene oxide from the salt solution.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: July 2, 1996
    Assignee: The Dow Chemical Company
    Inventors: David L. Trent, George J. Quarderer, Kim G. Bargeron, Douglas C. Greminger, David J. Koranek, Erik J. Stewart, Curtis N. Swisher, Cheryl A. Tirtowidjojo, Danil Tirtowidjojo