Patents by Inventor Clarence D. Chang

Clarence D. Chang 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).

  • Catalytic conversion over dehydroxylated zeolite
    Patent number: 4783571
    Abstract: The acidity of a zeolite catalyst is reduced by calcination in an essentially water-free atmosphere at temperatures above 700.degree. C., preferably from 725.degree. to 800.degree. C., to reduce the alpha value to less than 10 percent of its original value. The low acidity catalysts produced in this way may be used for isomerizing alkyl di-substituted aromatic compounds, especially xylenes, to products containing higher proportions of the para-isomers.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: November 8, 1988
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Stuart D. Hellring, Richard F. Socha
  • Organic compound conversion with ammonium hydroxide and alkali metal aluminate treated zeolite
    Patent number: 4780194
    Abstract: This invention relates to acid catalysis, e.g. cracking, of organic compound feedstock, e.g. hydrocarbons, over catalyst material treated in a special way for increasing the acid catalytic activity thereof. In particular, a novel catalyst activation process is followed to enhance the alpha value of high-silica zeolite catalyst by contact with an ammoniacal solution of ammonium hydroxide and an alkali metal aluminate under appropriate conditions of time, temperature of pH.
    Type: Grant
    Filed: September 18, 1986
    Date of Patent: October 25, 1988
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Synthesis of dioxane
    Patent number: 4760154
    Abstract: A catalyzed conversion of diethylene glycol to 1,4-dioxane, undertaken over zeolites, ZSM-5, ZSM-23, ZSM-48 and zeolite beta, is characterized by high selectivity.
    Type: Grant
    Filed: October 21, 1985
    Date of Patent: July 26, 1988
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Stuart D. Hellring
  • Production of high viscosity index lubricating oils from lower olefins
    Patent number: 4754096
    Abstract: A process for the production of lubricant oil range hydrocarbon having increased viscosity index by oligomerization of lower olefins over medium pore shape selective acid zeolite catalyst. The preferred oligomerization process is conducted using 50 ppm to 5 weight percent of water vapor as cofeed, based on olefin and acid ZSM-5 zeolite.
    Type: Grant
    Filed: July 13, 1987
    Date of Patent: June 28, 1988
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, John D. Dixon, Albert B. Schwartz, David S. Shihabi
  • Catalytic conversion over dehydroxylated zeolite
    Patent number: 4724270
    Abstract: The acidity of a zeolite catalyst is reduced by calcination in an essentially water-free atmosphere at temperatures above 700.degree. C., preferably from 725.degree. to 800.degree. C., to reduce the alpha value to less than 10 percent of its original value. The low acidity catalysts produced in this way may be used for conversions requiring low acidity, shape selective catalysis, including conversion of oxygenates to hydrocarbons. The calcined, low acidity catalysts exhibit improved selectivity to certain desired products.
    Type: Grant
    Filed: December 19, 1986
    Date of Patent: February 9, 1988
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Stuart D. Hellring, Richard F. Socha
  • Catalytic conversion
    Patent number: 4711970
    Abstract: A method for increasing the total amount of lattice metal in the framework of a particular porous inorganic crystalline composition, its conversion to hydrogen or hydronium form and use thereof as a catalyst component having enhanced catalytic activity for conversion of paraffins and/or olefins to higher hydrocarbons is provided.
    Type: Grant
    Filed: January 8, 1986
    Date of Patent: December 8, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Replacing boron with silicon in zeolite beta using SiCl.sub.4
    Patent number: 4701313
    Abstract: The present invention relates to siliceous zeolite catalysts produced by a method which includes selecting an amount of aluminum framework species to be retained in a zeolite catalyst product, and use of a silicon substitution treatment to replace more reactive framework species used to control aluminum framework concentration. This technique substantially preserves the selected amount of the aluminum framework species. The zeolite product obtained has high reactivity and stability.
    Type: Grant
    Filed: May 13, 1986
    Date of Patent: October 20, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Paul B. Weisz
  • Crystalline microporous oxide MCM-21 and process for its preparation
    Patent number: 4696807
    Abstract: This invention relates to a new synthetic crystalline microporous oxide material, a method for its preparation and use thereof in catalytic conversion of organic compounds. The new crystalline material exhibits a distinctive X-ray diffraction pattern.
    Type: Grant
    Filed: March 6, 1986
    Date of Patent: September 29, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Cynthia T-W Chu, Clarence D. Chang
  • Conversion of LPG hydrocarbons to distillate fuels or lubes using integration of LPG dehydrogenation and MOGDL
    Patent number: 4678645
    Abstract: A method and apparatus for producing distillate and/or lubes employs integrating catalytic (or thermal) dehydrogenation of paraffins with MOGDL. The process feeds the product from a low temperature propane and/or butane dehydrogenation zone into a first catalytic reactor zone, which operates at low pressure and contains zeolite oligomerization catalysts, where the low molecular weight olefins are reacted to primarily gasoline range materials. These gasoline range materials can then be pressurized to the pressure required for reacting to distillate in a second catalytic reactor zone operating at high pressure and containing a zeolite oligomerization catalyst. The distillate is subsequently sent to a hydrotreating unit and product separation zone to form lubes and other finished products.
    Type: Grant
    Filed: May 30, 1985
    Date of Patent: July 7, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joe E. Penick, Richard F. Socha
  • Method for reclaiming heat-damaged catalysts
    Patent number: 4678763
    Abstract: Heat-damaged ZSM-5 type catalysts are reclaimed by hydrothermal treatment with an aqueous medium followed by base exchange with an ammonium salt.
    Type: Grant
    Filed: January 17, 1986
    Date of Patent: July 7, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Modification of crystalline microporous zeolites
    Patent number: 4670412
    Abstract: Natural and synthetic micorporous crystalline minerals that have a robust three-dimensional framework are modified by treatment with a molten salt that contains a component that reacts with the framework. Highly siliceous ZSM-5 and some aluminum phosphate compositions are catalytically activated by this method.
    Type: Grant
    Filed: July 15, 1985
    Date of Patent: June 2, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Cynthia T. W. Chu, Joseph N. Miale
  • Zeolite modification and its use in conversion of alcohols and ethers to hydrocarbons
    Patent number: 4665248
    Abstract: The ion-exchange capacity and acid catalytic activity of a ZSM-5 type zeolite are increased by treatment of a physical mixture of the zeolite and an inorganic oxide with water in the presence of an alkali metal cation.Specifically, the catalyst is prepared by contacting a mixture of a crystalline zeolite having a silica to alumina ratio above 12 and a Constraint Index between about 1 and about 12, and a solid source of aluminum with liquid water in the presence of an activating amount of an alkali metal cation and under a combination of conditions including a temperature up to about 370.degree. C. for less than about an hour to about 100 hours to induce increased activity to the zeolite.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: May 12, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Catalytic conversion of aromatic compounds
    Patent number: 4665255
    Abstract: Feedstock comprising aromatic compounds is converted to product comprising aromatic compounds which differs from the feedstock over a catalyst which comprises a particular crystalline material which has been treated to increase the total amount of lattice metal in its framework. Examples of the conversion include alkylation, disproportionation, isomerization and transalkylation.
    Type: Grant
    Filed: January 8, 1986
    Date of Patent: May 12, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Formation of halogenated hydrocarbons from hydrocarbons
    Patent number: 4654449
    Abstract: Hydrocarbons and other compounds are halogenated to halocarbon products by contact with a halocarbon in the presence of an acidic zeolite catalyst such as ZSM-5. The process is particularly useful for the halogenation of methane to form chemicals of higher value.
    Type: Grant
    Filed: December 9, 1982
    Date of Patent: March 31, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Patrick D. Perkins
  • Catalytic conversion
    Patent number: 4645864
    Abstract: A method for increasing the total amount of lattice metal in the framework of a particular porous inorganic crystalline composition, its conversion to hydrogen or hydronium form and use thereof as a catalyst component having enhanced catalytic activity for conversion of oxygenates to hydrocarbons is provided.
    Type: Grant
    Filed: January 8, 1986
    Date of Patent: February 24, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Process for the preparation of zeolite Beta using dibenzyldimethylammonium ions and the product produced
    Patent number: 4642226
    Abstract: This invention relates to a new and improved form of crystalline silicate having the structure of zeolite Beta, to a new and useful improvement in synthesizing said crystalline silicate and to use of said crystalline silicate prepared in accordance herewith as a catalyst for organic compound, e.g. hydrocarbon compound, conversion.
    Type: Grant
    Filed: March 29, 1985
    Date of Patent: February 10, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Robert B. Calvert, Clarence D. Chang, Mae K. Rubin, Ernest W. Valyocsik
  • Acid-catalyzed xylene isomerization
    Patent number: 4638105
    Abstract: Feedstock comprising xylene isomers is converted to isomerization product by the present process over catalyst prepared by a method for substituting aluminum or gallium for boron or iron contained in the framework of a high silica content zeolite.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: January 20, 1987
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Catalytic cracking of using catalyst produced by novel process hydrocarbons
    Patent number: 4624774
    Abstract: A method for increasing the total amount of lattice metal in the framework of a particular porous inorganic crystalline composition, its conversion to hydrogen or hydronium form and use thereof as a catalyst component having enhanced catalyatic activity is provided.
    Type: Grant
    Filed: January 8, 1986
    Date of Patent: November 25, 1986
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Acid-catalyzed hydrocarbon conversion process
    Patent number: 4620921
    Abstract: Substitution of aluminum or gallium for boron or iron contained in the framework of a high silica content zeolite is effected by treating the zeolite in liquid water in the presence of a compound of aluminum or gallium. Catalyst comprising the treated zeolite is used for conducting acid-catalyzed reactions of organic compounds, e.g. cracking of hydrocarbon compounds.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: November 4, 1986
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale
  • Acid-catalyzed xylene isomerization
    Patent number: 4620054
    Abstract: This invention relates to acid catalysis of organic compound feedstock, e.g. isomerization of xylenes, over catalyst material treated in a special way for increasing the acid catalytic activity thereof. In particular, a novel catalyst activation process is followed to enhance the alpha value of high-silica zeolite catalyst by contact with an ammoniacal solution of an alkali metal aluminate under appropriate conditions of time, temperature and pH.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: October 28, 1986
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Joseph N. Miale