Patents by Inventor Dennis Leppin

Dennis Leppin 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: 9050557
    Abstract: A process for removing sulfur dioxide from a hydrogen sulfide-containing gas utilizes a bubble tower and overcomes process control difficulties associated with known processes. Solvent is fed to the bubble tower, loaded with sulfur dioxide and maintained at desired temperature and pressure. Hydrogen sulfide-containing gas is bubbled through the solvent, causing chemical reaction between the sulfur dioxide and hydrogen sulfide to yield water and elemental sulfur. Elemental sulfur is collected and ultimately discharged from the bottom of the bubble tower, and hydrogen sulfide-depleted gas is discharged from the top.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: June 9, 2015
    Assignee: Gas Technology Institute
    Inventors: Dennis Leppin, Ajay Makkuni, Timothy Tamale
  • Patent number: 8915981
    Abstract: A multi-stage method and apparatus for producing methane from biomass in which the biomass is hydropyrolyzed in a reactor vessel containing molecular hydrogen and a deoxygenating catalyst, the output of which is hydrogenated using a hydroconversion catalyst. The output from the hydroconversion step is provided to a water-gas-shift process providing a mixture of H2O and product gases including CO2, H2, and methane. The mixture components are separated, resulting in a product stream comprising substantially only methane.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: December 23, 2014
    Assignee: Gas Technology Institute
    Inventors: Terry L. Marker, Larry G. Felix, Martin B. Linck, Howard S. Meyer, Dennis Leppin
  • Patent number: 8268896
    Abstract: A method and system for co-production of electric power, fuel, and chemicals in which a synthesis gas at a first pressure is expanded using a stand-alone mechanical expander or a partial oxidation gas turbine, simultaneously producing electric power and an expanded synthesis gas at a second pressure after which the expanded synthesis gas is converted to a fuel and/or a chemical.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: September 18, 2012
    Assignee: Gas Technology Institute
    Inventors: Arunabha Basu, Iosif K Rabovitser, John J Lewnard, John M Pratapas, Howard S Meyer, Dennis Leppin, Dmitri Boulanov
  • Patent number: 8241603
    Abstract: A multi-stage UCSRP process and system for removal of sulfur from a gaseous stream in which the gaseous stream, which contains a first amount of H2S, is provided to a first stage UCSRP reactor vessel operating in an excess SO2 mode at a first amount of SO2, producing an effluent gas having a reduced amount of SO2, and in which the effluent gas is provided to a second stage UCSRP reactor vessel operating in an excess H2S mode, producing a product gas having an amount of H2S less than said first amount of H2S.
    Type: Grant
    Filed: March 22, 2011
    Date of Patent: August 14, 2012
    Assignee: Gas Technology Institute
    Inventors: Arunabha Basu, Howard S. Meyer, Scott Lynn, Dennis Leppin, James R. Wangerow
  • Publication number: 20110034569
    Abstract: A method and system for co-production of electric power, fuel, and chemicals in which a synthesis gas at a first pressure is expanded using a stand-alone mechanical expander or a partial oxidation gas turbine, simultaneously producing electric power and an expanded synthesis gas at a second pressure after which the expanded synthesis gas is converted to a fuel and/or a chemical.
    Type: Application
    Filed: February 2, 2010
    Publication date: February 10, 2011
    Applicant: GAS TECHNOLOGY INSTITUTE
    Inventors: Arunabha Basu, Iosif K. Rabovitser, John J. Lewnard, John M. Pratapas, Howard S. Meyer, Dennis Leppin, Dmitri Boulanov
  • Publication number: 20100303693
    Abstract: A hybrid solvent combining a physical solvent with particles of solid adsorbent for separation of components of a gas mixture, wherein both the physical solvent and the solid adsorbent particles are suitable for preferential removal of the components of interest.
    Type: Application
    Filed: July 10, 2009
    Publication date: December 2, 2010
    Applicant: GAS TECHNOLOGY INSTITUTE
    Inventor: Dennis Leppin
  • Patent number: 7811544
    Abstract: A method for recovering sulfur from a sulfur-bearing process gas stream in which a process gas stream comprising H2S and/or SO2 is contacted with a lean mixture of a lean UCSRP solution and a catalyst for promotion of a reaction between H2S and SO2 in anon-UCSRP vessel at a temperature below which H2S and SO2 react, whereby at least a portion of the H2S and/or SO2 is absorbed by the lean UCSRP solution, forming a rich mixture of a rich UCSRP solution and the catalyst. The rich mixture is introduced into a UCSRP vessel and heated to a reaction temperature greater than or equal to a melting temperature of sulfur, forming elemental sulfur and H2O.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: October 12, 2010
    Assignee: Gas Technology Institute
    Inventors: Dennis Leppin, Howard S. Meyer
  • Publication number: 20100251615
    Abstract: A multi-stage method and apparatus for producing methane from biomass in which the biomass is hydropyrolyzed in a reactor vessel containing molecular hydrogen and a deoxygenating catalyst, the output of which is hydrogenated using a hydroconversion catalyst. The output from the hydroconversion step is provided to a water-gas-shift process providing a mixture of H2O and product gases including CO2, H2, and methane. The mixture components are separated, resulting in a product stream comprising substantially only methane.
    Type: Application
    Filed: June 15, 2010
    Publication date: October 7, 2010
    Applicant: GAS TECHNOLOGY INSTITUTE
    Inventors: Terry L. Marker, Larry G. Felix, Martin B. Linck, Howard S. Meyer, Dennis Leppin
  • Patent number: 7544340
    Abstract: A method for contacting a liquid with a gas in which the gas is introduced into a vessel containing at least one hollow fiber membrane having a plurality of porous hollow fibers. The liquid is introduced into a lumen of at least a portion of the plurality of porous hollow fibers at a liquid pressure sufficient to overcome a resistance to wetting of the porous hollow fibers, thereby covering at least a portion of an outer surface of the plurality of porous hollow fibers with the liquid and providing intimate contact between the gas and the liquid.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: June 9, 2009
    Assignee: Gas Technology Institute
    Inventors: Aqil Jamal, Howard S. Meyer, Nagaraju Palla, Dennis Leppin
  • Publication number: 20080226525
    Abstract: A method for contacting a liquid with a gas in which the gas is introduced into a vessel containing at least one hollow fiber membrane having a plurality of porous hollow fibers. The liquid is introduced into a lumen of at least a portion of the plurality of porous hollow fibers at a liquid pressure sufficient to overcome a resistance to wetting of the porous hollow fibers, thereby covering at least a portion of an outer surface of the plurality of porous hollow fibers with the liquid and providing intimate contact between the gas and the liquid.
    Type: Application
    Filed: March 13, 2007
    Publication date: September 18, 2008
    Applicant: GAS TECHNOLOGY INSTITUTE
    Inventors: Aqil Jamal, Howard S. Meyer, Nagaraju Palla, Dennis Leppin
  • Patent number: 6946017
    Abstract: A process for separation of carbon dioxide and methane in which a gas mixture comprising carbon dioxide and methane is brought into contact with a methane hydrate solid material disposed in a reactor vessel, whereby the methane hydrate is displaced by carbon dioxide hydrate, thereby freeing the methane, which is then removed from the reactor vessel.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: September 20, 2005
    Assignee: Gas Technology Institute
    Inventors: Dennis Leppin, Alwarappa Sivaraman
  • Publication number: 20050120878
    Abstract: A process for separation of carbon dioxide and methane in which a gas mixture comprising carbon dioxide and methane is brought into contact with a methane hydrate solid material disposed in a reactor vessel, whereby the methane hydrate is displaced by carbon dioxide hydrate, thereby freeing the methane, which is then removed from the reactor vessel.
    Type: Application
    Filed: December 4, 2003
    Publication date: June 9, 2005
    Inventors: Dennis Leppin, Alwarappa Sivaraman
  • Patent number: 6475451
    Abstract: A process for removing mercury from a gaseous process stream. The process involves contacting a mercury-containing gaseous process stream with a regenerable mercury scavenger solution to form a treated stream having a reduced mercury content as compared to the mercury-containing gaseous process stream and a used scavenger solution having an increased mercury content. The regenerable mercury scavenger solution contains an oxidizing agent such as nitric acid, a complexing agent such as oxygen-containing agents and/or thiol and a solvent, for example, a mixture of methanol and water.
    Type: Grant
    Filed: August 23, 2000
    Date of Patent: November 5, 2002
    Assignee: Gas Technology Institute
    Inventors: Dennis Leppin, Nagaraju Palla
  • Patent number: 5958360
    Abstract: A method and apparatus for contacting a gas and a liquid such as may be utilized in removing sulfur from gas streams, using a liquid redox process, are provided, which prevent or avoid buildup of elemental sulfur in the process equipment by introducing the hydrogen sulfide contaminated gas through a plurality of gas inlets tangentially distributed within the inner wall of the reaction vessel containing a liquid redox scrubbing solution.
    Type: Grant
    Filed: February 6, 1998
    Date of Patent: September 28, 1999
    Assignee: Gas Research Institute
    Inventors: Amirali G. Rehmat, Michael C. Mensinger, Dennis Leppin
  • Patent number: 5876677
    Abstract: A method and apparatus for removing sulfur from gas streams, utilizing liquid redox, including an improved method for preventing build-up of elemental sulfur in a sulfur absorber. Ultrasonic irradiation of one or more portions of the structure of the absorber prevents sulfur build-up. In combination with monitoring of the pressure across the absorber, the freeing of sulfur from surfaces in an absorber can be automatically actuated.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: March 2, 1999
    Inventors: Michael C. Mensinger, Amirali G. Rehmat, Dennis Leppin
  • Patent number: 5866089
    Abstract: A method and apparatus for removing sulfur from gas streams, utilizing liquid redox, including an improved method for preventing build-up of elemental sulfur in a sulfur absorber. Ultrasonic irradiation of one or more portions of the structure of the absorber prevents sulfur build-up. In combination with monitoring of the pressure across the absorber, the freeing of sulfur from surfaces in an absorber can be automatically actuated.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: February 2, 1999
    Assignee: Gas Research Institute
    Inventors: Michael C. Mensinger, Amirali G. Rehmat, Dennis Leppin
  • Patent number: 5545296
    Abstract: A regenerating system, for the removal of water and potentially harmful organic constituents from a hydration fluid used to dehydrate natural gas. The system includes a device to assure positive flow of the water and organic constituent vapor out of the regenerator, to, in turn, control back pressure associated with the regenerator during the distillation process.
    Type: Grant
    Filed: April 27, 1995
    Date of Patent: August 13, 1996
    Assignee: Gas Research Institute
    Inventors: Vijay K. Pathak, Dennis Leppin
  • Patent number: 5531866
    Abstract: A regenerating system, for the removal of water and potentially harmful organic constituents from a dehydration fluid used to dehydrate natural gas. The system includes a device to assure positive flow of the water and organic constituent vapor out of the regenerator, to, in turn, control back pressure associated with the regenerator during the distillation process.
    Type: Grant
    Filed: December 6, 1994
    Date of Patent: July 2, 1996
    Assignee: Gas Research Institute
    Inventors: Vijay K. Pathak, Dennis Leppin