Patents Represented by Attorney D. M. Tuck
  • Patent number: 6932859
    Abstract: A composition of and a method of making high performance hollow fiber membranes is described. The membranes have a high resistance to plasticization by use of a predetermined amount of crosslinking. The preferred polymer material for the membrane is a polyimide polymer comprising covalently bonded ester crosslinks. The resultant hollow fiber membrane exhibits a high permeability of CO2 in combination with a high CO2/CH4 selectivity. Another embodiment provides a method of making the hollow fiber membrane from a monesterified polymer followed by final crosslinking after hollow fiber formation.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: August 23, 2005
    Assignees: Chevron USA Inc, University of Texas System
    Inventors: William J. Koros, David Wallace, John D. Wind, Stephen J. Miller, Claudia Staudt-Bickel
  • Patent number: 6803029
    Abstract: The present invention provides a process for suppressing the formation of metal-containing coke during processing of a hydrocarbonaceous material, such as for example a hydrocarbon conversion processes. The process involves using a feed comprising CO2 and steam in combination with equipment comprising high nickel and/or cobalt alloy metallurgy including aluminum or an aluminum coating in order to reduce metal catalyzed coking at process temperatures above about 800 degrees F. The process is particularly useful in the reforming of a hydrocarbon material to make hydrogen for operation in a fuel cell.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: October 12, 2004
    Assignee: Chevron U.S.A. Inc.
    Inventor: Gunther H. Dieckmann
  • Patent number: 6790433
    Abstract: The invention, in one embodiment, is a method for preparing crystalline zeolites by (a) contacting a calcined essentially aluminum free borosilicate zeolite with an aqueous acid solution, thereby producing an at least partially deboronated zeolite; (b) contacting said at least partially deboronated zeolite with a solution selected from the group consisting of an aqueous aluminum salt solution, thereby producing an aluminosilicate zeolite; an aqueous gallium salt solution, thereby producing a gallosilicate zeolite; an aqueous iron salt solution, thereby producing a ferrosilicate zeolite; and mixtures thereof; and (c) where the contacting in step (b) occurs at a pH of not greater than about 3.5.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: September 14, 2004
    Assignee: Chevron U.S.A. Inc.
    Inventors: Cong-Yan Chen, Stacey I. Zones
  • Patent number: 6790547
    Abstract: The present invention provides a process for suppressing the formation of metal-containing coke during processing of a hydrocarbonaceous material, such as for example a hydrocarbon conversion processes. Electromagnetic radiation is applied to the hydrocarbonaceous material while heating the hydrocarbonaceous material to a temperature above 700 degrees F. The frequency of the electromagnetic radiation is preferably below 300 MHz. The process is particularly useful in the reforming of a hydrocarbon material for operation in a fuel cell.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: September 14, 2004
    Assignee: Chevron U.S.A. Inc.
    Inventors: Gunther H. Dieckmann, Michael E. Moir
  • Patent number: 6755900
    Abstract: A composition of and a method of making high performance mixed matrix hollow fiber membranes is described. The membranes have a high resistance to plasticization by use of a predetermined amount of crosslinking. The preferred polymer material for the membrane is a polyimide polymer continuous phase comprising ester crosslinks and a molecular sieve material dispersed within the polymer continuous phase. The resultant mixed matrix hollow fiber membrane exhibits a high permeance of CO2 in combination with a high CO2/CH4 selectivity. Another embodiment provides a method of making the mixed matrix hollow fiber membrane from a monesterified polymer followed by final crosslinking after hollow fiber formation.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: June 29, 2004
    Assignees: Chevron U.S.A. Inc., University of Texas System
    Inventors: William J. Koros, David Wallace, John D. Wind, Stephen J. Miller, Claudia Staudt-Bickel, De Q. Vu
  • Patent number: 6063264
    Abstract: A process for catalytic reforming of feed hydrocarbons to form aromatics, comprising contacting the feed, under catalytic reforming conditions, with catalyst disposed in the tubes of a furnace, wherein the catalyst is a monofunctional, non-acidic catalyst and comprises a Group VIII metal and zeolite L, and wherein the furnace tubes are from 2 to 8 inches in inside diameter, and wherein the furnace tubes are heated, at least in part, by gas or oil burners located outside the furnace tubes.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: May 16, 2000
    Assignee: Chevron Chemical Company LLC
    Inventor: Nicholas J. Haritatos
  • Patent number: 6057487
    Abstract: A method is disclosed to produce 2,6-dimethylnaphthalene (2,6-DMN), used for the production of polyethylene naphthalate, at high purity and high yield from a mixture of dimethylnaphthalene isomers without limitation to the specific isomers present in the feed by a series of fractionation, crystallization and adsorption steps.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: May 2, 2000
    Assignee: Chevron Chemical Company
    Inventors: Curtis L. Munson, Patrick C. Bigot, Zunqing Alice He
  • Patent number: 6051744
    Abstract: A new process for the hydrodealkylation of ethylbenzene and the isomerization of xylenes at low pressure and at a low hydrogen to ethylbenzene mole ratio as well as a low hydrogen to hydrocarbon feed mole ratio using a catalyst comprising (a) HZSM-5 having a particle size less than 1.0 microns, and (b) a Group VIII metal such as platinum.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: April 18, 2000
    Assignee: Chevron Chemical Company LLC
    Inventors: Gerald J. Nacamuli, Charles R. Wilson, Roger F. Vogel