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).

  • Patent number: 6037513
    Abstract: There is described a process and a catalyst for the hydroalkylation of an aromatic hydrocarbon, particularly benzene, wherein the catalyst comprises a first metal having hydrogenation activity and a crystalline inorganic oxide material having a X-ray diffraction pattern including the following d-spacing maxima 12.4.+-.0.25, 6.9.+-.0.15, 3.57.+-.0.07 and 3.42.+-.0.07.
    Type: Grant
    Filed: July 9, 1998
    Date of Patent: March 14, 2000
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Jane C. Cheng, Terry E. Helton, Michael A. Steckel, Scott A. Stevenson
  • Patent number: 6008399
    Abstract: A process for preparing organic carbonates, such as dimethyl carbonate, without the use of phosgene and with a high yield and selectivity to the desired carbonate, by reacting a formaldehyde-acetal with a source of oxygen, in the presence of a catalyst.
    Type: Grant
    Filed: March 11, 1999
    Date of Patent: December 28, 1999
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Jose G. Santiesteban
  • Patent number: 5993643
    Abstract: There is provided a hydrocracking process using a catalyst comprising a hydrogenation/dehydrogenation component, such as a noble metal, and an acidic solid component comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. An example of this catalyst is zirconia, modified with tungstate and platinum. This catalyst is used to selectively hydrocrack naphtha range hydrocarbons to reduce the endpoint of reformulated gasolines.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: November 30, 1999
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Scott Han, Roger A. Morrison, Jose G. Santiesteban
  • Patent number: 5990365
    Abstract: There is provided a catalyst comprising ZSM-5, rhenium which is impregnated onto the catalyst, and a selectivating agent. The selectivating agent may be coke and/or a siliceous material. The catalyst is particularly useful for catalyzing toluene disproportionation reactions. Methods for making this catalyst and processes for using this catalyst in toluene disproportionation are also provided.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: November 23, 1999
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Frank T. DiGuiseppi, Scott Han
  • Patent number: 5902767
    Abstract: This invention is directed to a catalyst that comprises (i) an acidic solid oxide component comprising an oxide of a Group IVB metal modified with an anion or oxyanion of a Group VIB metal, and (ii) a Group IB metal or metal oxide component. This catalyst may be used, for example, to isomerize paraffins.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: May 11, 1999
    Assignee: Mobil Oil Corporation
    Inventors: Charles Theodore Kresge, Clarence D. Chang, Jose Guadalupe Santiesteban, David S. Shihabi, Scott Andrew Stevenson, James C. Vartuli
  • Patent number: 5854170
    Abstract: There is provided a method for preparing an acidic solid comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. An example of this acidic solid is zirconia, modified with tungstate. This modified solid oxide may be used as a catalyst, for example, to isomerize C.sub.4 to C.sub.8 paraffins. The modified solid oxide is treated with hydrogen at elevated temperatures to enhance catalytic properties of the material.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: December 29, 1998
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Frank T. DiGuiseppi, Scott Han, Jose G. Santiesteban, David L. Stern
  • Patent number: 5804690
    Abstract: A mono-methylation process for the production of methylated aromatics by reacting aromatics with dimethylcarbonate in the presence of a metal oxide or binary metal oxide catalyst. A process for preparing toluene from benzene by reacting with dimethylcarbonate and a process for preparing xylene from toluene by reacting with dimethylcarbonate are described.
    Type: Grant
    Filed: December 14, 1995
    Date of Patent: September 8, 1998
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Tracy J. Huang
  • Patent number: 5780703
    Abstract: A process for converting at least one olefin and at least one isoparaffin to a diesel fuel blending component comprising the steps of contacting the olefin and the isoparaffin with a catalyst comprising an acidic solid comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal to provide a diesel fuel. Process conditions can be varied to favor the formation of gasoline, distillate, lube range products or mixtures thereof.
    Type: Grant
    Filed: August 9, 1995
    Date of Patent: July 14, 1998
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Stuart D. Hellring, David O. Marler, Jose G. Santiesteban, James C. Vartuli
  • Patent number: 5780382
    Abstract: There is provided a method for preparing an acidic solid comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. An example of this acidic solid is zirconia, modified with tungstate. This modified solid oxide may be used as a catalyst, for example, to isomerize C.sub.4 to C.sub.8 paraffins. The method for preparing this acidic solid involves contacting a hydrated oxide of a Group IVB metal under hydrothermal conditions, such as reflux conditions, prior to contact of the hydrated oxide with an aqueous solution comprising a source of an oxyanion of a Group VIB metal.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: July 14, 1998
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Frank T. DiGuiseppi, Jose G. Santiesteban
  • Patent number: 5726114
    Abstract: A method of preparing a modified catalytic molecular sieve for enhanced shape selective hydrocarbon conversions in which a catalytic molecular sieve is modified by being exposed to at least one ex situ selectivation sequence, each sequence including an impregnation of the molecular sieve with a selectivating agent in an aqueous emulsion and a subsequent calcination of the impregnated molecular sieve. The selectivating agent compositions for the ex situ selectivation method are also described, including the selectivating agents, the surfactants, and the aqueous components. Also, a method for moderate steaming of the ex situ selectivated molecular sieve. Also a method for in situ trim-selectivating the ex situ selectivated catalytic molecular sieve. Also described is the modified catalytic molecular sieve modified by this method.
    Type: Grant
    Filed: August 17, 1995
    Date of Patent: March 10, 1998
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, John D. Lutner, Sharon B. McCullen, Paul G. Rodewald, David S. Shihabi
  • Patent number: 5719097
    Abstract: There is provided a catalyst comprising a hydrogenation/dehydrogenation component, such as a noble metal, and an acidic solid component comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. An example of this catalyst is zirconia, modified with tungstate and platinum. There is also provided a method for preparing this catalyst. This catalyst may be used, for example, to isomerize C.sub.4 to C.sub.8 paraffins. The feed to this paraffin isomerization reaction may, optionally, include cyclic hydrocarbons, such as benzene or cyclohexane, which may undergo ring opening reactions during the course of the isomerization reaction.
    Type: Grant
    Filed: July 22, 1996
    Date of Patent: February 17, 1998
    Inventors: Clarence D. Chang, Jose G. Santiesteban, David L. Stern
  • Patent number: 5608133
    Abstract: There is provided a catalytic oligomerization process. The process involves the use of a catalyst comprising an acidic solid. The acidic solid may comprise a Group IVB metal oxide, such as zirconia, modified with an oxyanion of a Group VIB metal, such as tungsten. The oligomers produced by this process may be hydrogenated to produce thermally stable lubricants and lubricant additives, gasoline and diesel.
    Type: Grant
    Filed: October 23, 1995
    Date of Patent: March 4, 1997
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Tracy J. Huang, Jose G. Santiesteban, James C. Vartuli
  • Patent number: 5607888
    Abstract: A process and catalyst for Shape Selective Hydrocarbon Conversions such as the regioselective disproportionation of toluene to para-xylene wherein hydrocarbon to be converted is passed over a catalytic molecular sieve which is trim selectivated with a reaction stream comprising toluene and a silicon-containing high efficiency p-xylene selectivating agent under toluene conversion conditions. The toluene disproportionation process attains a single-pass para-xylene product over 95% coupled with a toluene conversion of at least 15%. The present invention also includes the highly para-selective catalyst which results from the treatment of a catalytic molecular sieve with a high efficiency p-xylene selectivating agent under the recited conditions.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: March 4, 1997
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Paul G. Rodewald
  • Patent number: 5571768
    Abstract: There is provided a zeolite, such as ZSM-5, which is functionalized with at least one organosiliceous group of the formula, SiR.sub.n (OX).sub.4-n, where R is at least one hydrocarbyl group, n is 1 or 2 and X is Si or H. There is also provided a method for functionalizing a zeolite by treatment with a silicone compound, such as hexamethyldisiloxane, under vapor phase conditions. This contacting may take place in the presence of hydrogen and an organic carrier. The functionalized zeolites may provide a catalyst which is both highly active and highly selective for converting aromatic hydrocarbons, especially alkylbenzene compounds, to products comprising the para-isomer of dialkylbenzenes. The disproportionation of toluene is an example of such a reaction.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: November 5, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Paul G. Rodewald
  • Patent number: 5563311
    Abstract: Relatively short chain alkyl aromatic compounds are prepared by alkylating or transalkylating an alkylatable aromatic compound with a relatively short chain alkylating or transalkylating agent under sufficient reaction conditions in the presence of catalyst comprising an acidic solid material which comprises a Group IVB metal oxide, such as zirconia, modified with an oxyanion of a Group VIB metal, such as tungsten.
    Type: Grant
    Filed: December 28, 1994
    Date of Patent: October 8, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Jane C. Cheng, Scott Han, Jos e G. Santiesteban, Dennis E. Walsh
  • Patent number: 5563310
    Abstract: A process for the conversion of toluene to xylenes by alkylation with methanol over an acidic solid catalyst with a Group IVB metal oxide modified with an oxyanion of a Group VIB metal.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: October 8, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Frank T. DiGuiseppi, Scott Han
  • Patent number: 5552128
    Abstract: There is provided a catalytic method for converting nitrogen oxides to nitrogen (i.e., N.sub.2). The catalyst for this method comprises an acidic solid component comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal and further comprising at least one metal selected from the group consisting of Group IB, Group IVA, Group VB, Group VIIB, Group VIII, and mixtures thereof. An example of this catalyst is zirconia, modified with tungstate, and iron. This method may be used for reducing emissions of nitrogen oxides from waste gases, including industrial exhaust gases and automobile exhaust gases. In a particular embodiment, nitrogen oxides in waste gases may be reacted with ammonia before the waste gases are discharged to the atmosphere.
    Type: Grant
    Filed: March 24, 1995
    Date of Patent: September 3, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Jose G. Santiesteban, David S. Shihabi, Scott A. Stevenson, James C. Vartuli
  • Patent number: 5543036
    Abstract: A process for hydrotreating a hydrocarbon feedstock, such as light cycle oil, using a catalyst composition containing a hydrogenation/dehydrogenation component and an acidic solid component including a Group IVB metal oxide modified with an oxyanion of a Group VIB metal. The hydrotreating process removes contaminants, such as sulfur and/or nitrogen, from the feedstock.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: August 6, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Scott Han, Daniel J. Martenak, Jose G. Santiesteban, Dennis E. Walsh
  • Patent number: 5541146
    Abstract: A catalytic molecular sieve which has been preselectivated by agglomerating with an organosilicon compound. The invention also includes a method for agglomeration-preselectivation and the shape selective catalyst which results from the agglomeration preselectivation.
    Type: Grant
    Filed: August 3, 1994
    Date of Patent: July 30, 1996
    Assignee: Mobil Oil Corporation
    Inventors: Clarence D. Chang, Cynthia T-W. Chu, Thomas F. Degnan, Paul G. Rodewald, David S. Shihabi
  • Patent number: 5516736
    Abstract: There is provided a method for selectivating a zeolite, such as ZSM-5 which may result in functionalization of the zeolite with at least one organosiliceous group of the formula, SiR.sub.n (OX).sub.4-n, where R is at least one hydrocarbyl group, n is 1 or 2 and X is Si or H. This selectivation method involves vapor phase treatment of a zeolite with an organosilicon compound having at least 2 silicon atoms. This organosilicon compound may be a silicone compound, such as hexamethyldisiloxane, or a silane compound such as hexamethyldisilane. This contacting may take place in the presence of hydrogen and an organic carrier. The functionalized zeolites may provide a catalyst which is both highly active and highly selective for converting aromatic hydrocarbons, especially alkylbenzene compounds, to products comprising the para-isomer of dialkylbenzenes. The disproportionation of toluene is an example of such a reaction.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: May 14, 1996
    Assignee: Mobil Oil Corp.
    Inventors: Clarence D. Chang, Paul G. Rodewald