Patents by Inventor Chang W. Chi

Chang W. Chi 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: 4424144
    Abstract: Shaped products of a 3A zeolite are formed either as beads or extrudates without any binder remaining. In the case of beads, a 4A powder is mixed with a caustic solution and a metakaolin clay binder to form beads. The beads are converted to a binderless 4A product which is given a partial calcium exchange followed by a potassium exchange to obtain the desired 3A binderless bead. The 3A extrudates are produced by forming binderless 4A extrudates from a 4A powder and clay mixture that contains 40-60% by weight clay. These binderless 4A extrudates are then given a potassium exchange. Both the beads and the extrudates can be used to dry a mixture of a hydrocarbon compound such as ethylene and water.
    Type: Grant
    Filed: November 16, 1981
    Date of Patent: January 3, 1984
    Assignee: W. R. Grace & Co.
    Inventors: James N. Pryor, Chang W. Chi
  • Patent number: 4381255
    Abstract: Binderless zeolite sieve extrudates are made by extruding a mixture containing about 40-60% zeolites with the remainder being a metakaolin clay that has mixed with it about 90-120% of the stoichiometric amount of sodium hydroxide to convert the clay to a zeolite. After extrusion the particles are allowed to dry age during which time most of the clay is converted to the zeolite. A further heat treatment in a dilute caustic aqueous solution insures complete crystallization with subsequent washing and calcination to produce an adsorbent product.
    Type: Grant
    Filed: January 14, 1981
    Date of Patent: April 26, 1983
    Assignee: W. R. Grace & Co.
    Inventors: Richard J. Nozemack, Chang W. Chi, John J. Schwonke