Patents by Inventor Chih-Hao M. Tsang

Chih-Hao M. Tsang 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: 6706199
    Abstract: The present invention relates to an apparatus and method for withdrawing and dewatering slag from a gasification system. In particular, the present invention relates to a conveying lockhopper and method of using the conveying lockhopper to collect slag and other waste byproducts from the gasifier of a gasification system. The conveying lockhopper is configured to receive slag from a gasifier, simultaneously extract and dewater the slag, and expel the processed slag directly into an awaiting container suitable for carrying the processed slag away. The conveying lockhopper generally comprises a housing with inlet and outlet valves to receive and expel slag, respectively. The housing is inclined at an angle typically between 5 and 60 degrees to the horizontal so that the outlet is at a higher elevation than the inlet. Inside the housing, an auger or similar conveying mechanism conveys the slag from the inlet towards the outlet while simultaneously dewatering the slag.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: March 16, 2004
    Assignees: Texaco Inc., Texaco Development Corporation
    Inventors: John D. Winter, Rajasekar Kamarthi, Thomas F. Leininger, Katherine S. Lee, Chih-Hao M. Tsang, Pravit Vassantachart
  • Publication number: 20010032780
    Abstract: The present invention relates to an apparatus and method for withdrawing and dewatering slag from a gasification system. In particular, the present invention relates to a conveying lockhopper and method of using the conveying lockhopper to collect slag and other waste byproducts from the gasifier of a gasification system. The conveying lockhopper is configured to receive slag from a gasifier, simultaneously extract and dewater the slag, and expel the processed slag directly into an awaiting container suitable for carrying the processed slag away. The conveying lockhopper generally comprises a housing with inlet and outlet valves to receive and expel slag, respectively. The housing is inclined at an angle typically between 5 and 60 degrees to the horizontal so that the outlet is at a higher elevation than the inlet. Inside the housing, an auger or similar conveying mechanism conveys the slag from the inlet towards the outlet while simultaneously dewatering the slag.
    Type: Application
    Filed: February 13, 2001
    Publication date: October 25, 2001
    Inventors: John D. Winter, Rajasekar Kamarthi, Thomas F. Leininger, Katherine S. Lee, Chih-Hao M. Tsang, Pravit Vassantachart
  • Publication number: 20010026783
    Abstract: The present invention relates to an apparatus and method for withdrawing and dewatering slag from a gasification system. In particular, the present invention relates to a conveying lockhopper and method of using the conveying lockhopper to collect slag and other waste byproducts from the gasifier of a gasification system. The conveying lockhopper is configured to receive slag from a gasifier, simultaneously extract and dewater the slag, and expel the processed slag directly into an awaiting container suitable for carrying the processed slag away. The conveying lockhopper generally comprises a housing with inlet and outlet valves to receive and expel slag, respectively. The housing is inclined at an angle typically between 5 and 60 degrees to the horizontal so that the outlet is at a higher elevation than the inlet. Inside the housing, an auger or similar conveying mechanism conveys the slag from the inlet towards the outlet while simultaneously dewatering the slag.
    Type: Application
    Filed: February 13, 2001
    Publication date: October 4, 2001
    Inventors: John D. Winter, Rajasekar Kamarthi, Thomas F. Leininger, Katherine S. Lee, Chih-Hao M. Tsang, Pravit Vassantachart
  • Patent number: 5549813
    Abstract: Disclosed is a fluid catalytic cracking process for cracking gas oils and naphtha which provides improved selectivity for C.sub.3 -C.sub.5 olefins employing a catalyst comprising a novel zeolite characterized by a large number of secondary pores, a substantially decreased Lattice Constant of below about 24.19 .ANG., and a substantially decreased Acid Site Density, attained by hydrothermal and acid-treating of an ultrastable Y-zeolite.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: August 27, 1996
    Inventors: Pei-Shing E. Dai, Chih-Hao M. Tsang, Laurence D. Neff, Randall H. Petty
  • Patent number: 5472594
    Abstract: Disclosed is a process for converting a hydrocarbon charge to a product containing improved yields of C.sub.4 /C.sub.5 olefins with a reduction in the loss of gasoline yield which comprises:passing said hydrocarbon charge into contact with a catalyst comprising a phosphorus-containing medium pore zeolite mixed as an additive with Y-zeolite in a weight ratio of 0.005 to 0.10, said zeolites in separate or composite spray dried particles,wherein the catalyst to oil ratio is 0.1 to 10, reacting said hydrocarbon charge at a temperature of 800.degree. F. to 1200.degree. F., a pressure of 0 to 150 psig, and in the absence of added hydrogen, thereby producing a product containing improved yields of C.sub.4 /.sub.5 olefins and reduced loss in gasoline yield.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: December 5, 1995
    Assignee: Texaco Inc.
    Inventors: Chih-Hao M. Tsang, Laurence D. Neff, Pei-Shing E. Dai
  • Patent number: 5395512
    Abstract: A hydrocarbon feedstock is catalytically cracked at an elevated temperature in a cracking zone with a zeolite cracking catalyst. The cracking catalyst employed comprises a crystalline aluminosilicate zeolite catalyst and a hybrid [Al,B]-zeolite catalyst. In this process the hydrocarbon feedstock is contacted with the zeolite catalyst in, for example, a fluidized bed catalytic cracking unit to yield cracked products containing increased amounts of C.sub.3 /C.sub.8 olefins.
    Type: Grant
    Filed: May 14, 1993
    Date of Patent: March 7, 1995
    Assignee: Texaco Inc.
    Inventors: Hsu-Hui Hsing, Roy E. Pratt, Chih-Hao M. Tsang, Chi-Lin O'Young
  • Patent number: 5114901
    Abstract: In a preferred method, particles of amorphous silica are used to provide a silica coating suitable for carrying dispersed catalyst particles for the treatment of diesel engine exhaust emissions. The silica coating is formed from a mixture consisting essentially of two groups of the fine silica particles of respective average sizes and size ranges which are virtually non-overlapping. The particles of the first of the two groups have a first average size sufficient to permit the particles of the first group (smaller group) to occupy voids between the particles of the second group (larger group) in a packed arrangement, and preferably the second group has a second average size which is at least 20 times greater than the first average size.
    Type: Grant
    Filed: February 19, 1991
    Date of Patent: May 19, 1992
    Assignee: General Motors Corporation
    Inventors: Chih-Hao M. Tsang, Raymond E. Bedford
  • Patent number: 5081095
    Abstract: A high surface area ceria-alumina washcoat is disclosed in which the ceria is prepared from cerium acetate.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: January 14, 1992
    Assignee: General Motors Corporation
    Inventors: Raymond E. Bedford, Chih-Hao M. Tsang