Patents by Inventor Wan J. Cheng

Wan J. Cheng 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: 4866179
    Abstract: An improved method of catalytic gaseous chemical synthesis of pyridine by reaction of ammonia and a carbonyl compound, preferably with added hydrogen, is described herein. The process employs as the catalyst a crystalline aluminosilicate zeolite which has been ion exchanged with a Group VIII metal of the Periodic Table. The preferred metal is palladium. Suitably, the Group VIII metal is present in an amount of about 0.01% to 5% by weight of the catalyst, preferably 0.1% to 2%. The crystalline aluminosilicate zeolite catalyst suitably has a silica to alumina mole rate of at least 15, preferably 30 to 200, and optimally, about 120 to 150. The process of the invention provides a high and selective yield of pyridine over a prolonged reaction period, and affords facile restorability of the catalyst.
    Type: Grant
    Filed: June 6, 1988
    Date of Patent: September 12, 1989
    Assignee: Dairen Chemical Corporation
    Inventors: Wan J. Cheng, Fu S. Lin, Yuh L. Jong, Fu J. Huang