Patents by Inventor Dennis L. Holtermann

Dennis L. Holtermann 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: 5914028
    Abstract: A catalytic reforming process using a halided zeolite catalyst containing platinum in a metal-coated reactor system where, prior to catalyst loading and reforming, halide acid is removed from the catalyst. The process comprises providing a reforming reactor system having a metal coating; providing a halided zeolite catalyst containing platinum prepared by a method which includes removing volatile halide acid; loading said catalyst into said reactor system; and catalytically reforming hydrocarbons to aromatics, wherein metal from the metal-coated reactor system does not deactivate the catalyst. The coating metal preferably comprises tin and the zeolite catalyst is preferably a platinum L-zeolite catalyst. The invention is also a method for reducing catalyst contamination from a metal which was used to coat a reactor system. The method comprises pretreating a halided catalyst with hydrogen to remove volatile halide acid.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: June 22, 1999
    Assignee: Chevron Chemical Company
    Inventors: Charles R. Wilson, Dennis L. Holtermann
  • Patent number: 5883031
    Abstract: A process for regenerating a coke contaminated reforming catalyst comprising platinum on a molecular sieve, said process consisting essentially of contacting said catalyst with a halogen-free oxygen-containing gas at a temperature of less than 780.degree. F. for a sufficient period of time such that the aromatization activity is restored to within 20.degree. F. of the activity said catalyst possessed at the start of the previous run cycle.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: March 16, 1999
    Assignee: Chevron Chemical Company
    Inventors: Robert A. Innes, Dennis L. Holtermann, Bernard F. Mulaskey
  • Patent number: 5693215
    Abstract: A crystalline low-aluminum boron beta zeolite is used for dewaxing hydrocarbonaceous feeds.
    Type: Grant
    Filed: October 30, 1996
    Date of Patent: December 2, 1997
    Assignee: Chevron U.S.A. Inc.
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Lawrence W. Jossens, Donald S. Santilli, Andrew Rainis, James N. Ziemer
  • Patent number: 5691463
    Abstract: A crystalline zeolite SSZ-25 is prepared using an adamantane quaternary ammonium ion as a template.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: November 25, 1997
    Assignee: Chevron U.S.A. Inc.
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Robert A. Innes, Theresa A. Pecoraro, Donald S. Santilli, James N. Ziemer
  • Patent number: 5591322
    Abstract: A crystalline zeolite SSZ-25 is prepared using an adamantane quaternary ammonium ion as a template.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: January 7, 1997
    Assignee: Chevron U.S.A. Inc.
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Robert A. Innes, Theresa A. Pecoraro, Donald S. Santilli, James N. Ziemer
  • Patent number: 5518607
    Abstract: A process is disclosed for removing residual sulfur from a hydrotreated naphtha feedstock. The feedstock is contacted with molecular hydrogen under reforming conditions in the presence of a less sulfur sensitive reforming catalyst to convert trace sulfur compounds to H.sub.2 S, and to form a first effluent. The first effluent is contacted with a solid sulfur sorbent to remove the H.sub.2 S and form a second effluent. The second effluent is then contacted with a highly selective reforming catalyst under severe reforming conditions. Also disclosed is a method using a potassium containing sulfur sorbent made from nitrogen-free potassium compounds.
    Type: Grant
    Filed: January 4, 1993
    Date of Patent: May 21, 1996
    Inventors: Leslie A. Field, Ann Marie K. Hall, Richard C. Robinson, Robert L. Jacobson, Warren E. Brown, Dennis L. Holtermann
  • Patent number: 5516421
    Abstract: A process for reducing the amount of down time or yield loss associated with a sulfur upset when using a sulfur-sensitive catalyst. The process comprises applying a metallic coat, cladding, plating or paint to a reactor system which comprises a base metal, so as to form an adherent metallic layer on the base metal and thereby produce a metal-coated reactor system; loading a sulfur-sensitive catalyst into the system; and, after a sulfur upset, using a process comprising sulfur stripping to remove sulfur contaminants from the metal-coated reactor system.
    Type: Grant
    Filed: August 17, 1994
    Date of Patent: May 14, 1996
    Inventors: Warren E. Brown, Dennis L. Holtermann, John V. Heyse
  • Patent number: 5439583
    Abstract: A process is disclosed for removing residual sulfur from a hydrotreated naphtha feedstock. The feedstock is contacted with molecular hydrogen under reforming conditions in the presence of a less sulfur sensitive reforming catalyst to convert trace sulfur compounds to H.sub.2 S, and to form a first effluent. The first effluent is contacted with a solid sulfur sorbent to remove the H.sub.2 S and form a second effluent. The second effluent is then contacted with a highly selective reforming catalyst under severe reforming conditions. Also disclosed is a method using a potassium containing sulfur sorbent made from nitrogen-free potassium compounds.
    Type: Grant
    Filed: January 4, 1993
    Date of Patent: August 8, 1995
    Assignee: Chevron Research and Technology Company
    Inventors: Richard C. Robinson, Robert L. Jacobson, Harris E. Kluksdahl, William A. Blanton, Dennis L. Holtermann, Leslie A. Field
  • Patent number: 5421992
    Abstract: A crystalline zeolite SSZ-25 is prepared using an adamantane quaternary ammonium ion as a template.
    Type: Grant
    Filed: June 11, 1992
    Date of Patent: June 6, 1995
    Assignee: Chevron U.S.A. Inc.
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Robert A. Innes, Theresa A. Pecoraro, Donald S. Santilli, James N. Ziemer
  • Patent number: 5397454
    Abstract: A crystalline zeolite SSZ-32 of novel composition is prepared using an N-lower alkyl-N'-isopropyl-imidazolium cation as a template. Also disclosed is a process for converting hydrocarbons with crystalline zeolite SSZ-32.
    Type: Grant
    Filed: February 28, 1994
    Date of Patent: March 14, 1995
    Assignee: Chevron U.S.A. Inc.
    Inventors: Stacey I. Zones, James N. Ziemer, Donald S. Santilli, Robert A. Innes, Dennis L. Holtermann
  • Patent number: 5393407
    Abstract: A crystalline low-aluminum boron beta zeolite is prepared using a diquaternary ion as a template.
    Type: Grant
    Filed: June 26, 1992
    Date of Patent: February 28, 1995
    Assignee: Chevron Research Company
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Lawrence W. Jossens, Donald S. Santilli, Andrew Rainis
  • Patent number: 5322615
    Abstract: Provided is a method for removing residual sulfur from a hydrotreated naphtha feedstock. The process comprises contacting the naphtha feedstock with a first solid sulfur sorbent comprising a metal on a support to thereby form a first effluent. The effluent is then contacted with a sulfur conversion catalyst comprising a Group VIII metal in the presence of hydrogen, with the resulting effluent being contacted with a second solid sulfur sorbent containing a Group IA or IIA metal, to thereby lower the sulfur content of the feedstock to less than 10 ppb, and to as low as 1 ppb or less. The feedstock can then be safely used with highly sulfur sensitive zeolitic reforming catalysts without adversely affecting the useful life of the catalyst.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: June 21, 1994
    Assignee: Chevron Research and Technology Company
    Inventors: Dennis L. Holtermann, Warren E. Brown
  • Patent number: 5300210
    Abstract: A crystalline zeolite SSZ-32 of novel composition is prepared using an N-lower alkyl-N'-isopropyl-imidazolium cation as a template. Also disclosed is a process for converting hydrocarbons with crystalline zeolite SSZ-32.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: April 5, 1994
    Assignee: Chevron Research and Technology Company
    Inventors: Stacey I. Zones, James N. Ziemer, Donald S. Santilli, Robert A. Innes, Dennis L. Holtermann
  • Patent number: 5202014
    Abstract: A crystalline zeolite SSZ-25 is prepared using an adamantane quaternary ammonium ion as a template.
    Type: Grant
    Filed: November 6, 1991
    Date of Patent: April 13, 1993
    Assignee: Chevron Research and Technology Company
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Robert A. Innes, Theresa A. Pecoraro, Donald S. Santilli, James N. Ziemer
  • Patent number: 5200377
    Abstract: A crystalline zeolite SSZ-28 is prepared using an N,N-dimethyl-tropinium or N,N-dimethyl-3-azonium bicyclo[3.2.2]nonane cation as a template. Also disclosed is a process for converting hydrocarbons with crystalline zeolite SSZ-28.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: April 6, 1993
    Assignee: Chevron Research and Technology Company
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Robert A. Innes
  • Patent number: 5166111
    Abstract: A crystalline low-aluminum boron beta zeolite is prepared using a diquaternary ion as a template.
    Type: Grant
    Filed: October 9, 1990
    Date of Patent: November 24, 1992
    Assignee: Chevron Research Company
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Lawrence W. Jossens, Donald S. Santilli, Andrew Rainis
  • Patent number: 5166112
    Abstract: The present invention is a process and a catalyst for isomerizing normal and slightly branched C.sub.4 to C.sub.7 hydrocarbons. The catalyst comprises a Group VIII metal on Beta zeolite.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: November 24, 1992
    Assignee: Chevron Research Company
    Inventor: Dennis L. Holtermann
  • Patent number: 5155075
    Abstract: A process for regenerating a coke contaminated reforming catalyst comprising platinum on a molecular sieve, said process consisting essentially of contacting said catalyst with a halogen-free oxygen-containing gas at a temperature of less than 780.degree. F. for a sufficient period of time such that the aromatization activity is restored to within 20.degree. F. of the activity said catalyst possessed at the start of the previous run cycle.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: October 13, 1992
    Assignee: Chevron Research and Technology Company
    Inventors: Robert A. Innes, Dennis L. Holtermann, Bernard F. Mulaskey
  • Patent number: 5149894
    Abstract: A process for the alkylation of an aromatic hydrocarbon which comprises contacting the aromatic hydrocarbon with a C.sub.2 to C.sub.4 olefin alkylating agent under at least partial liquid phase conditions, and in the presence of a catalyst comprising zeolite SSZ-25. The invention also provides a process for producing a reduced benzene content gasoline blend stock. A benzene-containing light hydrocarbon stream having less than 50 weight present benzene is contacted with a C.sub.2 -C.sub.4 olefin stream in an alkylation zone containing an SSZ-25 catalyst under alkylation conditions to produce an alkylated light hydrocarbon stream with reduced benzene content. The alkylated light hydrocarbon stream is then usable as gasoline blend stock.
    Type: Grant
    Filed: August 15, 1991
    Date of Patent: September 22, 1992
    Assignee: Chevron Research and Technology Company
    Inventors: Dennis L. Holtermann, Robert A. Innes
  • Patent number: 5120425
    Abstract: A crystalline zeolite SSZ-33 is prepared using a quaternary ion as a template wherein said zeolite is used in hydrocarbon conversion processes.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: June 9, 1992
    Assignee: Chevron Research Company
    Inventors: Stacey I. Zones, Dennis L. Holtermann, Donald S. Santilli, Lawrence W. Jossens, James V. Kennedy, Andrew Rainis