Patents by Inventor David L. Stern

David L. Stern 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: 7485763
    Abstract: In a process for converting C9+ aromatic hydrocarbons to lighter aromatic products a feed comprising C9+ aromatic hydrocarbons is contacted under transalkylation reaction conditions with a catalyst composition comprising (i) a first molecular sieve selected from the group consisting of ZSM-12, mordenite and a porous crystalline inorganic oxide material having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07; and (ii) a second molecular sieve having a constraint index ranging from 3 to 12. At least the first molecular sieve has a hydrogenation component associated therewith and the first and second molecular sieves are contained in the same catalyst bed. The C9+ aromatic hydrocarbons are converted under the transalkylation reaction conditions to a reaction product containing xylene.
    Type: Grant
    Filed: November 3, 2006
    Date of Patent: February 3, 2009
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: John Scott Buchanan, Ronald J. Cimini, Robert A. Crane, Wenyih F. Lai, Jose G. Santiesteban, David A. Stachelczyk, David L. Stern, Hye-Kyung C. Timken, William A. Weber
  • Publication number: 20090007782
    Abstract: The management of hydrogen in hydrogen-containing streams associated with petrochemical process units wherein the hydrogen-containing stream is subjected rapid cycle pressure swing adsorption to increase the concentration of hydrogen therein.
    Type: Application
    Filed: January 23, 2006
    Publication date: January 8, 2009
    Inventors: David L. Stern, Bal K. Kaul, John Di-Yi Ou, Dana L. Pilliod
  • Publication number: 20080282892
    Abstract: The present invention relates to engineered structured adsorbent contactors for use in pressure swing adsorption and thermal swing adsorption processes. Preferably, the contactors contain engineered and substantially parallel flow channels wherein 20 volume percent or less of the open pore volume of the contactor, excluding the flow channels, is in the mesopore and macropore range.
    Type: Application
    Filed: April 4, 2008
    Publication date: November 20, 2008
    Inventors: Harry W. Deckman, Ronald R. Chance, Edward W. Corcoran, JR., David L. Stern
  • Publication number: 20080237129
    Abstract: This invention relates to a process for recycling acid used to remove nitrogen contaminants from hydrocarbons using polymeric membranes to separate spent acid from the acid extraction of hydrocarbons into acid for recycle and acid for regeneration.
    Type: Application
    Filed: December 1, 2004
    Publication date: October 2, 2008
    Applicant: ExxonMobil Research and Engineering Company
    Inventors: Bhupender S. Minhas, Dennis G. Peiffer, Jeffrey S. Beck, David L. Stern, Tomas R. Melli
  • Patent number: 7390933
    Abstract: In a process for reducing the Bromine Index of a feed containing a linear alkylbenzene and bromine-reactive olefinic hydrocarbon contaminants, the feed is contacted under conditions effective to remove bromine-reactive olefinic hydrocarbon contaminants with a catalyst comprising zeolite Y catalyst having an alpha value of about 2 to about 30. The feed will normally also contain benzene and linear paraffin remaining from the alkylation process used to produce the linear alkylbenzene.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: June 24, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Frederick Y. Lo, David L. Stern, Ronald J. Cimini, James L. Propp
  • Patent number: 7361798
    Abstract: The invention relates to a process for producing a desired dialkylbenzene isomer having a formula R2C6H4, where R is an alkyl substituent, by contacting a polyalkylbenzene compound of formula RnC6H6-n, where n is an integer between 2 and 4, with a monoalkylbenzene compound of formula RC6H5 in the presence of a molecular sieve catalyst under reaction conditions sufficient to produce said dialkybenzene isomer. The preferred molecular sieve catalysts have pores or surface cavities greater than 5.6 Angstroms in diameter and/or an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07, and 3.42±0.07 Angstrom.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: April 22, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Michael C. Clark, Ronald J. Cimini, Jane C. Cheng, David L. Stern, John Scott Buchanan
  • Patent number: 7326332
    Abstract: A multi component catalyst and catalytic cracking process for selectively producing C3 olefins. The catalyst comprises a first molecular sieve having an intermediate pore size, a second molecular sieve and, optionally a third molecular sieve having a large pore size. At least one of the channels of the second molecular sieve has a pore size index that is less than the pore size index of at least one channel of the first molecular sieve. The process is carried out by contacting a feedstock containing hydrocarbons having at least 5 carbon atoms is contacted, under catalytic cracking conditions, with the multi component catalyst. The catalyst finds application in the cracking of naphtha and heavy hydrocarbon feedstocks.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: February 5, 2008
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Tan-Jen Chen, John Scott Buchanan, Brian Erik Henry, Paul F. Keusenkothen, Philip A. Ruziska, David L. Stern
  • Patent number: 7288181
    Abstract: The instant invention relates to a process to produce high octane, low sulfur naphtha products through the removal of basic nitrogen-containing compounds with subsequent skeletal isomerization of feed olefins and hydrotreating.
    Type: Grant
    Filed: July 9, 2004
    Date of Patent: October 30, 2007
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Stuart S. Shih, David L. Stern, Madhav Acharya
  • Patent number: 7271118
    Abstract: A catalyst system that exhibits a ratio of ethylene saturation to aromatics ring saturation of greater than 3,500. The catalyst system comprises two components and each component comprises a crystalline molecular sieve having a Constraint Index of from about 1 to about 12 and an effective amount of Group VIII metal. The catalyst system finds particular application in ethylbenzene conversion/xylenes isomerization reactions. The catalyst system can be prepared by incorporating the Group VIII metal into the molecular sieves by competitive ion exchange.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: September 18, 2007
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Brenda A. Raich, Robert A. Crane, Christine N. Elia, Teresa A. Jurgens-Kowal, Gary D. Mohr, David L. Stern
  • Patent number: 7247762
    Abstract: A process for the isomerization of xylenes and the conversion of ethylbenzene to benzene and ethane using a catalyst system comprising two catalysts. The first catalyst is unselectivated and comprises: (a) an intermediate pore size zeolite, e.g., ZSM-5; (b) at least one hydrogenation component to deethylate ethylbenzene, e.g. Group VIII and/or Group VIIIB metal; and (c) an amorphous binder, said first catalyst requiring at least 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury. The second catalyst comprises an intermediate pore size zeolite, e.g., ZSM-5, and requires less than 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury. The amount of first catalyst present in the catalyst system is a volume greater than 55 percent based on the sum of the volumes of the first catalyst and second catalyst.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: July 24, 2007
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventor: David L. Stern
  • Patent number: 7238636
    Abstract: A method is disclosed for modifying a catalytic molecular sieve for shape-selective hydrocarbon conversions comprises: a) selectivating said catalytic molecular sieve by contacting with a silicon-containing selectivating agent; and b) calcining the selectivated catalytic molecular sieve at high temperature calcination conditions comprising temperatures greater than 700° C., which conditions are sufficient to reduce acid activity as measured by alpha value and increase diffusion barrier of said catalytic molecular sieve as measured by the rate of 2,3-dimethylbutane uptake, as compared to the selectivated catalyst. Catalytic molecular sieves thus prepared, such as silica-bound ZSM-5, and their use in hydrocarbon conversion processes such as aromatics isomerization, e.g., xylene isomerization, ethylbenzene conversion and aromatics disproportionation, e.g., toluene disproportionation are also disclosed.
    Type: Grant
    Filed: July 23, 2003
    Date of Patent: July 3, 2007
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Jeffrey S. Beck, William G. Borghard, Arthur W. Chester, Carrie L. Kennedy, David L. Stern
  • Patent number: 7214840
    Abstract: In a process for reducing the Bromine Index of a feed containing a linear alkylbenzene and bromine-reactive olefinic hydrocarbon contaminants, the feed is contacted under conditions effective to remove bromine-reactive olefinic hydrocarbon contaminants with a catalyst comprising zeolite Y catalyst having an alpha value of about 2 to about 30. The feed will normally also contain benzene and linear paraffin remaining from the alkylation process used to produce the linear alkylbenzene.
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: May 8, 2007
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Frederick Y. Lo, David L. Stern, Ronald J. Cimini, James L. Propp
  • Patent number: 7166756
    Abstract: The present invention is directed at a process to isomerize C10+ hydrocarbon feedstreams by contacting a C10+ hydrocarbon feedstream with a steamed catalyst.
    Type: Grant
    Filed: November 25, 2003
    Date of Patent: January 23, 2007
    Assignee: Exxonmobil Research and Engineering Company
    Inventors: Madhav Acharya, David L. Stern
  • Patent number: 7148391
    Abstract: In a process for converting C9+ aromatic hydrocarbons to lighter aromatic products a feed comprising C9+ aromatic hydrocarbons is contacted under transalkylation reaction conditions with a catalyst composition comprising (i) a first molecular sieve selected from the group consisting of ZSM-12, mordenite and a porous crystalline inorganic oxide material having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07; and (ii) a second molecular sieve having a constraint index ranging from 3 to 12. At least the first molecular sieve has a hydrogenation component associated therewith and the first and second molecular sieves are contained in the same catalyst bed. The C9+ aromatic hydrocarbons are converted under the transalkylation reaction conditions to a reaction product containing xylene.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: December 12, 2006
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: John Scott Buchanan, Ronald J. Cimini, Frank Wenyih Lai, Jose G. Santiesteban, David A. Stachelczyk, David L. Stern, Hye-Kyung C. Timken, William A. Weber, Robert A. Crane
  • Patent number: 7115538
    Abstract: An ethylbenzene conversion catalyst is described which comprises a molecular sieve and a hydrogenation metal, wherein the catalyst exhibits a benzene hydrogenation activity at 100° C. of less than about 100 and a metal dispersion, as measured by hydrogen chemisorption, greater than 0.4 and wherein the molecular sieve is steamed to an alpha value of less than 400 prior to incorporation of the palladium with the molecular sieve.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: October 3, 2006
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: John Scott Buchanan, Robert A. Crane, Doron Levin, Daria N. Lissy, Gary D. Mohr, David L. Stern
  • Patent number: 6878654
    Abstract: The present invention provides a process for regenerating a spent aromatics alkylation or transalkylation catalyst comprising a molecular sieve by contacting the spent catalyst with an oxygen-containing gas at a temperature of about 120 to about 600° C. and then contacting the catalyst with an aqueous medium, such as an ammonium nitrate solution, an ammonium carbonate solution or an acid solution.
    Type: Grant
    Filed: September 13, 2002
    Date of Patent: April 12, 2005
    Assignee: ExxonMobil Chemical Patents Inc.
    Inventors: Ajit B. Dandekar, Michael Hryniszak, Jeffrey S. Beck, David L. Stern, Kathleen M. Keville
  • Publication number: 20040222157
    Abstract: A method for recovering acid from a feed mixture comprising acid, hydrocarbons and water, the method comprising:
    Type: Application
    Filed: February 6, 2004
    Publication date: November 11, 2004
    Inventors: Bhupender S. Minhas, Dennis G. Peiffer, Jorge L. Soto, David L. Stern, Tomas R. Melli, Jeffrey S. Beck, Steven Ackerman, David C. Dalrymple, Alexander D.S. Fremuth, Walter Weissman, Frederick J. Krambeck
  • Publication number: 20040214713
    Abstract: An ethylbenzene conversion catalyst is described which comprises a molecular sieve and a hydrogenation metal, wherein the catalyst exhibits a benzene hydrogenation activity at 100° C. of less than about 100 and a metal dispersion, as measured by hydrogen chemisorption, greater than 0.4 and wherein the molecular sieve is steamed to an alpha value of less than 400 prior to incorporation of the palladium with the molecular sieve.
    Type: Application
    Filed: December 4, 2002
    Publication date: October 28, 2004
    Inventors: John Scott Buchanan, Robert A. Crane, Doron Levin, Daria N. Lissy, Gary D. Mohr, David L. Stern
  • Publication number: 20040162455
    Abstract: The present invention is directed at a process to isomerize C10+ hydrocarbon feedstreams by contacting a C10+ hydrocarbon feedstream with a steamed catalyst.
    Type: Application
    Filed: November 25, 2003
    Publication date: August 19, 2004
    Applicant: ExxonMobil Research and Engineering Company
    Inventors: Madhav Acharya, David L. Stern
  • Patent number: 6777583
    Abstract: There is provided a substantially binder-free catalytic molecular sieve which has been modified by being ex situ selectivated with a silicon compound. The ex situ selectivation involves exposing the molecular sieve to at least two silicon impregnation sequences, each sequence comprising an impregnation with a silicon compound followed by calcination. The catalyst may be used in a hydrocarbon conversion process, such as toluene disproportionation.
    Type: Grant
    Filed: August 26, 2002
    Date of Patent: August 17, 2004
    Assignee: ExxonMobil Oil Corporation
    Inventors: Jeffrey S. Beck, Jane C. Cheng, Sharon B. McCullen, David H. Olson, David L. Stern