Patents by Inventor George W. Roberts

George W. Roberts 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: 7410620
    Abstract: A method for carrying out the continuous polymerization of a monomer in a carbon dioxide reaction medium comprises the steps of: (a) providing an apparatus including a continuous reaction vessel and a separator; (b) carrying out a polymerization reaction in the reaction vessel by combining a monomer and a carbon dioxide reaction medium therein (and preferably by also combining an initiator therein), wherein the reaction medium is a liquid or supercritical fluid, and wherein the reaction produces a solid polymer product in the reaction vessel; then (c) withdrawing a continuous effluent stream from the reaction vessel during the polymerization reaction, wherein the effluent stream is maintained as a liquid or supercritical fluid; then (d) passing the continuous effluent stream through the separator and separating the solid polymer therefrom while maintaining at least a portion of the effluent stream as a liquid or supercritical fluid; and then (e) returning at least a portion of the continuous effluent stream t
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: August 12, 2008
    Assignee: North Carolina State University
    Inventors: Paul A. Charpentier, Joseph M. DeSimone, George W. Roberts
  • Patent number: 7408009
    Abstract: A method of hydrogenating a polymer comprises: (a) providing a dense phase, the dense phase comprising a polymer in a solvent; (b) providing a catalyst system, the catalyst system comprising as least one metal hydrogenation catalyst (preferably including nickel or ruthenium); and (c) providing a light phase, the light phase comprising, consisting of or consisting essentially of hydrogen and carbon dioxide; and (d) contacting the dense phase, the light phase and the catalyst system under conditions in which the hydrogen reacts with the polymer and hydrogenates the polymer.
    Type: Grant
    Filed: November 3, 2003
    Date of Patent: August 5, 2008
    Assignee: North Carolina State University
    Inventors: George W. Roberts, Dawei Xu, Douglas J. Kiserow, Ruben G. Carbonell
  • Patent number: 7063839
    Abstract: A method for continuously separating polymer from a high pressure fluid stream comprises subjecting the high pressure fluid stream comprising polymer particles to a filter, wherein the filter segregates the high pressure fluid stream from the polymer particles; subjecting the polymer particles to a rotating device which transports the polymer particles away from the filter, wherein the polymer particles are exposed to thermal conditions sufficient to melt the polymer particles and form a seal surrounding at least a portion of the rotating device; and separating the molten polymer from the rotating device. The method is carried out such that the separation of polymer from the high pressure fluid stream occurs under steady-state.
    Type: Grant
    Filed: October 18, 2004
    Date of Patent: June 20, 2006
    Assignee: North Carolina State University
    Inventors: Joseph R. Royer, George W. Roberts
  • Patent number: 6919383
    Abstract: A method of depolymerizing a polymer comprises contacting a polymer with a fluid comprising carbon dioxide and at least one component, wherein the fluid plasticizes the polymer and facilitates penetration of the component into the polymer to depolymerize the polymer and form oligomeric units, monomeric units, or combinations thereof.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: July 19, 2005
    Assignee: North Carolina State University
    Inventors: Saad A. Khan, George W. Roberts, Joseph R. Royer
  • Patent number: 6914105
    Abstract: A method for carrying out the continuous polymerization of a monomer in a carbon dioxide reaction medium comprises the steps of: (a) providing an apparatus including a continuous reaction vessel and a separator; (b) carrying out a polymerization reaction in the reaction vessel by combining a monomer and a carbon dioxide reaction medium therein (and preferably by also combining an initiator therein), wherein the reaction medium is a liquid or supercritical fluid, and wherein the reaction produces a solid polymer product in the reaction vessel; then (c) withdrawing a continuous effluent stream from the reaction vessel during the polymerization reaction, wherein the effluent stream is maintained as a liquid or supercritical fluid; then (d) passing the continuous effluent stream through the separator and separating the solid polymer therefrom while maintaining at least a portion of the effluent stream as a liquid or supercritical fluid; and then (e) returning at least a portion of the continuous effluent stream t
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: July 5, 2005
    Assignees: North Carolina State University, The University of North Carolina at Chapel Hill
    Inventors: Paul A. Charpentier, Joseph M. DeSimone, George W. Roberts
  • Patent number: 6900267
    Abstract: Methods of carrying out a reactive extrusion processes are described that include combining at least one polymer, oligomer, or combination thereof, a carbon dioxide containing fluid, and at least one reactant in an extruder to form a mixture such that the carbon dioxide containing fluid comes into intimate contact with the at least one polymer, oligomer, or combination thereof and assists in a reaction between the at least one polymer, oligomer, or combination thereof and the at least one reactant, and wherein the at least one polymer, oligomer, or combination thereof is modified upon reaction with the at least one reactant.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: May 31, 2005
    Assignees: North Carolina State University, The University of North Carolina at Chapel Hill
    Inventors: Joseph Royer, Joseph M. DeSimone, George W. Roberts, Saad A. Khan
  • Patent number: 6806332
    Abstract: A method for continuously separating polymer from a high pressure fluid stream comprises subjecting the high pressure fluid stream comprising polymer particles to a filter, wherein the filter segregates the high pressure fluid stream from the polymer particles; subjecting the polymer particles to a rotating device which transports the polymer particles away from the filter, wherein the polymer particles are exposed to thermal conditions sufficient to melt the polymer particles and form a seal surrounding at least a portion of the rotating device; and separating the molten polymer from the rotating device. The method is carried out such that the separation of polymer from the high pressure fluid stream occurs under steady-state.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: October 19, 2004
    Assignee: North Carolina State University
    Inventors: Joseph R. Royer, George W. Roberts
  • Publication number: 20040162404
    Abstract: A method for forming a fluoropolymer comprises providing a reaction mixture comprising carbon dioxide, at least one fluoromonomer, and an initiator; and reacting the at least one fluoromonomer in the reaction mixture to form a fluoropolymer. The fluoropolymer has a multimodal molecular weight distribution.
    Type: Application
    Filed: February 13, 2004
    Publication date: August 19, 2004
    Applicants: University of North Carolina at Chapel Hill, North Carolina State University
    Inventors: Joseph M. DeSimone, George W. Roberts, Paul A. Charpentier
  • Patent number: 6716945
    Abstract: A method for forming a fluoropolymer comprises providing a reaction mixture comprising carbon dioxide, at least one fluoromonomer, and an initiator; and reacting the at least one fluoromonomer in the reaction mixture to form a fluoropolymer. The fluoropolymer has a multimodal molecular weight distribution.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: April 6, 2004
    Assignees: North Carolina State University, University of North Carolina at Chapel Hill
    Inventors: Joseph M. DeSimone, George W. Roberts, Paul A. Charpentier
  • Publication number: 20030171495
    Abstract: Methods of carrying out a reactive extrusion processes are described that include combining at least one polymer, oligomer, or combination thereof, a carbon dioxide containing fluid, and at least one reactant in an extruder to form a mixture such that the carbon dioxide containing fluid comes into intimate contact with the at least one polymer, oligomer, or combination thereof and assists in a reaction between the at least one polymer, oligomer, or combination thereof and the at least one reactant, and wherein the at least one polymer, oligomer, or combination thereof is modified upon reaction with the at least one reactant.
    Type: Application
    Filed: December 12, 2002
    Publication date: September 11, 2003
    Inventors: Joseph Royer, Joseph M. DeSimone, George W. Roberts, Saad A. Khan
  • Publication number: 20030072690
    Abstract: A method for continuously separating polymer from a high pressure fluid stream comprises subjecting the high pressure fluid stream comprising polymer particles to a filter, wherein the filter segregates the high pressure fluid stream from the polymer particles; subjecting the polymer particles to a rotating device which transports the polymer particles away from the filter, wherein the polymer particles are exposed to thermal conditions sufficient to melt the polymer particles and form a seal surrounding at least a portion of the rotating device; and separating the molten polymer from the rotating device. The method is carried out such that the separation of polymer from the high pressure fluid stream occurs under steady-state.
    Type: Application
    Filed: February 25, 2002
    Publication date: April 17, 2003
    Inventors: Joseph R. Royer, George W. Roberts
  • Publication number: 20020169223
    Abstract: A method of depolymerizing a polymer comprises contacting a polymer with a fluid comprising carbon dioxide and at least one component, wherein the fluid plasticizes the polymer and facilitates penetration of the component into the polymer to depolymerize the polymer and form oligomeric units, monomeric units, or combinations thereof.
    Type: Application
    Filed: April 10, 2002
    Publication date: November 14, 2002
    Inventors: Saad A. Khan, George W. Roberts, Joseph R. Royer
  • Publication number: 20020040118
    Abstract: A method for forming a fluoropolymer comprises providing a reaction mixture comprising carbon dioxide, at least one fluoromonomer, and an initiator; and reacting the at least one fluoromonomer in the reaction mixture to form a fluoropolymer. The fluoropolymer has a multimodal molecular weight distribution.
    Type: Application
    Filed: May 18, 2001
    Publication date: April 4, 2002
    Inventors: Joseph M. DeSimone, George W. Roberts, Paul A. Charpentier
  • Patent number: 6217830
    Abstract: A method of separating a Fischer-Tropsch catalyst from the output slurry of a Fischer-Tropsch bubble column reactor, where the slurry comprises Fischer-Tropsch catalyst particles and liquid hydrocarbon product is disclosed. The method comprises contacting a compressed hydrocarbon solvent (e.g., a supercritical hydrocarbon solvent, or liquid hydrocarbon solvent which may be at near supercritical conditions) with the output slurry at a temperature and pressure where the liquid hydrocarbon product is soluble in the solvent to form a concentrated slurry phase containing the catalyst particles, and an enriched solvent phase containing liquid hydrocarbon product. This contacting step is then followed by the step of separating the concentrated slurry from the enriched solvent. Apparatus for carrying out the method of the invention is also disclosed.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: April 17, 2001
    Assignee: North Carolina State University
    Inventors: George W. Roberts, Peter K. Kilpatrick
  • Patent number: 6114399
    Abstract: A method of separating a Fischer-Tropsch catalyst from the output slurry of a Fischer-Tropsch bubble column reactor, where the slurry comprises Fischer-Tropsch catalyst particles and liquid hydrocarbon product is disclosed. The method comprises contacting a compressed hydrocarbon solvent (e.g., a supercritical hydrocarbon solvent, or liquid hydrocarbon solvent which may be at near supercritical conditions) with the output slurry at a temperature and pressure where the liquid hydrocarbon product is soluble in the solvent to form a concentrated slurry phase containing the catalyst particles, and an enriched solvent phase containing liquid hydrocarbon product. This contacting step is then followed by the step of separating the concentrated slurry from the enriched solvent. Apparatus for carrying out the method of the invention is also disclosed.
    Type: Grant
    Filed: February 6, 1997
    Date of Patent: September 5, 2000
    Assignee: North Carolina State University
    Inventors: George W. Roberts, Peter K. Kilpatrick
  • Patent number: 4859435
    Abstract: The present invention is directed to a process for removing minor amounts of oxygen from inert gas streams to result in very low levels of oxygen contamination in such inert gas streams, wherein the oxygen is removed by the action of stoichiometric quantities of methanol, which react with the oxygen over a catalyst at ambient feed temperature conditions without a requirement for external heating of the reaction.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: August 22, 1989
    Assignee: Air Products and Chemicals, Inc.
    Inventors: George W. Roberts, Shivaji Sircar, Paul Stepanoff
  • Patent number: 4859434
    Abstract: The present invention is directed to a process for producing endothermic gases from methanol and inert gas streams containing minor amounts of oxygen, wherein the oxygen is reacted with stoichiometric excess quantities of methanol over a catalyst as ambient feed temperature conditions without a requirement for external heating of the reaction to produce an endothermic gas containing very low levels of oxygen and methanol and significant quantities of hydrogen, carbon monoxide, water and carbon dioxide.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: August 22, 1989
    Assignee: Air Products and Chemicals, Inc.
    Inventors: George W. Roberts, Shivaji Sircar, Paul Stepanoff
  • Patent number: 4801574
    Abstract: The present invention relates to a method of activation of a CuO/ZnO/Al.sub.2 O.sub.3 catalyst slurried in a chemically inert liquid. Successful activation of the catalyst requires the use of a process in which the temperature of the system at any time is not allowed to exceed a certain critical value, which is a function of the specific hydrogen uptake of the catalyst at that same time. This process is especially critical for activating highly concentrated catalyst slurries, typically 25 to 50 wt %. Activation of slurries of CuO/ZnO/Al.sub.2 O.sub.3 catalyst is useful in carrying out the liquid phase methanol or the liquid phase shift reactions.
    Type: Grant
    Filed: December 2, 1987
    Date of Patent: January 31, 1989
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Dennis M. Brown, Thomas H. Hsiung, Pradip Rao, George W. Roberts
  • Patent number: 4766154
    Abstract: The present invention is a process for the production of methanol from a syngas feed containing carbon monoxide, carbon dioxide and hydrogen. Basically, the process is the combination of two liquid phase methanol reactors into a staging process, such that each reactor is operated to favor a particular reaction mechanism. In the first reactor, the operation is controlled to favor the hydrogenation of carbon monoxide, and in the second reactor, the operation is controlled so as to favor the hydrogenation of carbon dioxide. This staging process results in substantial increases in methanol yield.
    Type: Grant
    Filed: February 6, 1987
    Date of Patent: August 23, 1988
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Leo W. Bonnell, Alan T. Perka, George W. Roberts
  • Patent number: 4690215
    Abstract: Enhanced oil recovery from a crude oil reservoir is promoted following primary oil production, by subjecting the reservoir to water flooding, discontinuing the water flooding, preferably when the remaining oil is at an OIP level above 0.10, and then subjecting the reservoir to fireflooding with gas having an O.sub.2 content of at least 50%, preferably above 85%.
    Type: Grant
    Filed: May 16, 1986
    Date of Patent: September 1, 1987
    Assignee: Air Products and Chemicals, Inc.
    Inventors: George W. Roberts, James G. Hansel, Goutam H. Shahani