Patents Assigned to Cha Corporation
  • Patent number: 8431083
    Abstract: The invention is an apparatus and method to remove hydrogen sulfide and siloxanes from biogas and destroy the contaminants in microwave reactors. Hydrogen sulfide and siloxane are removed from biogas using an adsorbent media such as activated carbon. The media is regenerated in a microwave reactor where the hydrogen sulfide and siloxane are removed in a sweep gas. In one process, siloxane is oxidized to silicon dioxide in a second microwave reactor and removed with a filter. Hydrogen sulfide if first oxidized to sulfur dioxide, then reduced to sulfur in a third microwave reactor and removed with a filter. In another process, siloxane is combined with water to form silicon dioxide and hydrogen sulfide is reduced to elemental sulfur in a microwave reactor. These reactants are removed with a filter. The remaining sweep gas containing hydrogen and low molecular weight hydrocarbons is returned to the biogas stream.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: April 30, 2013
    Assignees: Cha Corporation, C-Micro Systems, Inc.
    Inventor: Chang Yul Cha
  • Publication number: 20120301366
    Abstract: The invention is an apparatus and method to remove hydrogen sulfide and siloxanes from biogas and destroy the contaminants in microwave reactors. Hydrogen sulfide and siloxane are removed from biogas using an adsorbent media such as activated carbon. The media is regenerated in a microwave reactor where the hydrogen sulfide and siloxane are removed in a sweep gas. In one process, siloxane is oxidized to silicon dioxide in a second microwave reactor and removed with a filter. Hydrogen sulfide if first oxidized to sulfur dioxide, then reduced to sulfur in a third microwave reactor and removed with a filter. In another process, siloxane is combined with water to form silicon dioxide and hydrogen sulfide is reduced to elemental sulfur in a microwave reactor. These reactants are removed with a filter. The remaining sweep gas containing hydrogen and low molecular weight hydrocarbons is returned to the biogas stream.
    Type: Application
    Filed: February 3, 2012
    Publication date: November 29, 2012
    Applicant: CHA CORPORATION
    Inventor: Chang Yul Cha
  • Patent number: 8168126
    Abstract: The invention is an apparatus and method to remove hydrogen sulfide and siloxanes from biogas and destroy the contaminants in microwave reactors. Hydrogen sulfide and siloxane are removed from biogas using an adsorbent media such as activated carbon. The media is regenerated in a microwave reactor where the hydrogen sulfide and siloxane are removed in a sweep gas. In one process, siloxane is oxidized to silicon dioxide in a second microwave reactor and removed with a filter. Hydrogen sulfide if first oxidized to sulfur dioxide, then reduced to sulfur in a third microwave reactor and removed with a filter. In another process, siloxane is combined with water to form silicon dioxide and hydrogen sulfide is reduced to elemental sulfur in a microwave reactor. These reactants are removed with a filter. The remaining sweep gas containing hydrogen and low molecular weight hydrocarbons is returned to the biogas stream.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: May 1, 2012
    Assignee: Cha Corporation
    Inventor: Chang Yul Cha
  • Publication number: 20110280773
    Abstract: The invention is an apparatus and method to remove hydrogen sulfide and siloxanes from biogas and destroy the contaminants in microwave reactors. Hydrogen sulfide and siloxane are removed from biogas using an adsorbent media such as activated carbon. The media is regenerated in a microwave reactor where the hydrogen sulfide and siloxane are removed in a sweep gas. In one process, siloxane is oxidized to silicon dioxide in a second microwave reactor and removed with a filter. Hydrogen sulfide if first oxidized to sulfur dioxide, then reduced to sulfur in a third microwave reactor and removed with a filter. In another process, siloxane is combined with water to form silicon dioxide and hydrogen sulfide is reduced to elemental sulfur in a microwave reactor. These reactants are removed with a filter. The remaining sweep gas containing hydrogen and low molecular weight hydrocarbons is returned to the biogas stream.
    Type: Application
    Filed: May 3, 2011
    Publication date: November 17, 2011
    Applicant: CHA CORPORATION
    Inventor: Chang Yul Cha
  • Patent number: 7960303
    Abstract: The invention is an apparatus and method to remove hydrogen sulfide and siloxanes from biogas and destroy the contaminants in microwave reactors. Hydrogen sulfide and siloxane are removed from biogas using an adsorbent media such as activated carbon. The media is regenerated in a microwave reactor where the hydrogen sulfide and siloxane are removed in a sweep gas. In one process, siloxane is oxidized to silicon dioxide in a second microwave reactor and removed with a filter. Hydrogen sulfide if first oxidized to sulfur dioxide, then reduced to sulfur in a third microwave reactor and removed with a filter. In another process, siloxane is combined with water to form silicon dioxide and hydrogen sulfide is reduced to elemental sulfur in a microwave reactor. These reactants are removed with a filter. The remaining sweep gas containing hydrogen and low molecular weight hydrocarbons is returned to the biogas stream.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: June 14, 2011
    Assignee: CHA Corporation
    Inventor: Chang Yul Cha
  • Publication number: 20100143209
    Abstract: Granulated Activated Carbon (GAC) is used to remove hydrogen sulfide (H2S) from the biogas produced in an anaerobic digester. The cleaned biogas is then combusted in a reciprocating engine. The exhaust of the engine is passed through a heat exchanger and then through GAC in an adsorber to adsorb nitrogen oxides (NOx) and any sulfur oxides (SOx). The GACs containing NOx, H2S, and SOx, are transported to a microwave reactor, mixed, and exposed to microwave energy. The H2S and NOx are desorbed from the GAC and chemically combined to produce nitrogen, carbon dioxide, sulfur and water. Unreacted nitrogen oxides or hydrogen sulfide are transported to a second reactor containing carbon media to be reacted by a further microwave process. Sulfur is removed with a filter as a solid and the remaining inert components are vented to the atmosphere. The GAC is regenerated and reused to remove additional H2S and NOx.
    Type: Application
    Filed: November 18, 2009
    Publication date: June 10, 2010
    Applicant: CHA CORPORATION
    Inventor: CHANG YUL CHA
  • Patent number: 7641874
    Abstract: Granulated Activated Carbon (GAC) is used to remove hydrogen sulfide (H2S) from the biogas produced in an anaerobic digester. The cleaned biogas is then combusted in a reciprocating engine. The exhaust of the engine is passed through a heat exchanger and then through GAC in an adsorber to adsorb nitrogen oxides (NOx) and any sulfur oxides (SOx). The GACs containing NOx, H2S, and SOx, are transported to a microwave reactor, mixed, and exposed to microwave energy. The H2S and NOx are desorbed from the GAC and chemically combined to produce nitrogen, carbon dioxide, sulfur and water. Unreacted nitrogen oxides or hydrogen sulfide are transported to a second reactor containing carbon media to be reacted by a further microwave process. Sulfur is removed with a filter as a solid and the remaining inert components are vented to the atmosphere. The GAC is regenerated and reused to remove additional H2S and NOx.
    Type: Grant
    Filed: January 14, 2008
    Date of Patent: January 5, 2010
    Assignee: CHA Corporation
    Inventor: Chang Yul Cha
  • Publication number: 20080197013
    Abstract: Granulated Activated Carbon (GAC) is used to remove hydrogen sulfide (H2S) from the biogas produced in an anaerobic digester. The cleaned biogas is then combusted in a reciprocating engine. The exhaust of the engine is passed through a heat exchanger and then through GAC in an adsorber to adsorb nitrogen oxides (NOx) and any sulfur oxides (SOx). The GACs containing NOx, H2S, and SOx, are transported to a microwave reactor, mixed, and exposed to microwave energy. The H2S and NOx are desorbed from the GAC and chemically combined to produce nitrogen, carbon dioxide, sulfur and water. Unreacted nitrogen oxides or hydrogen sulfide are transported to a second reactor containing carbon media to be reacted by a further microwave process. Sulfur is removed with a filter as a solid and the remaining inert components are vented to the atmosphere. The GAC is regenerated and reused to remove additional H2S and NOx.
    Type: Application
    Filed: January 14, 2008
    Publication date: August 21, 2008
    Applicant: CHA CORPORATION
    Inventor: CHANG YUL CHA
  • Publication number: 20080179177
    Abstract: The invention is an apparatus and method to remove hydrogen sulfide and siloxanes from biogas and destroy the contaminants in microwave reactors. Hydrogen sulfide and siloxane are removed from biogas using an adsorbent media such as activated carbon. The media is regenerated in a microwave reactor where the hydrogen sulfide and siloxane are removed in a sweep gas. In one process, siloxane is oxidized to silicon dioxide in a second microwave reactor and removed with a filter. Hydrogen sulfide if first oxidized to sulfur dioxide, then reduced to sulfur in a third microwave reactor and removed with a filter. In another process, siloxane is combined with water to form silicon dioxide and hydrogen sulfide is reduced to elemental sulfur in a microwave reactor. These reactants are removed with a filter. The remaining sweep gas containing hydrogen and low molecular weight hydrocarbons is returned to the biogas stream.
    Type: Application
    Filed: January 14, 2008
    Publication date: July 31, 2008
    Applicant: CHA CORPORATION
    Inventor: CHANG YUL CHA
  • Patent number: 6284202
    Abstract: The subject invention is a commercial device to effectively remove NOx and other pollutants from an exhaust gas stream. Microwave enhancement of oxidation/reduction catalysis is selectively employed as the exhaust gas stream traverses a bed of catalyst particles, which may operate as either a fixed or fluidized bed. An unique feature involves the conventional, non-microwave, conversion of NO to NO2; however, the subsequent reaction of reducing NO2 is microwave enhanced.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: September 4, 2001
    Assignee: Cha Corporation
    Inventors: Chang Yul Cha, Charles T. Carlisle
  • Patent number: 6046376
    Abstract: Gaseous decomposition from a solution is enhanced in the presence of activated carbon or its equivalent by radiofrequency energy in the microwave range. An important example is wet calcination using solutions containing bicarbonates, such as trona, where good conversion to carbonate is readily obtained. A further example is the excellent stabilization of solutions containing sulfites and bisulfites.
    Type: Grant
    Filed: October 15, 1998
    Date of Patent: April 4, 2000
    Assignee: Cha Corporation
    Inventors: Chang Yul Cha, Charles T. Carlisle