초록 ▼

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 nit

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.

대표청구항 ▼

What is claimed is: 1. A method for removing hydrogen sulfide and nitrogen oxides from carbon media, comprising: providing a first microwave reactor adapted to receive first carbon media containing hydrogen sulfide and nitrogen oxides; providing a source of microwave energy in said first reactor; p

What is claimed is: 1. A method for removing hydrogen sulfide and nitrogen oxides from carbon media, comprising: providing a first microwave reactor adapted to receive first carbon media containing hydrogen sulfide and nitrogen oxides; providing a source of microwave energy in said first reactor; providing a source of sweep gas to said first microwave reactor; positioning first carbon media containing hydrogen sulfide and nitrogen oxides in said first microwave reactor; applying microwave energy to desorb hydrogen sulfide and nitrogen oxides from said first carbon media; reacting said hydrogen sulfide with said nitrogen oxide to form nitrogen, water and sulfur in said first reactor; and transporting nitrogen, water and sulfur from said first microwave reactor in said sweep gas. 2. A method as recited in claim 1, further comprising: providing a particulate filter fluidly connected to said first microwave reactor; and removing sulfur in said filter. 3. A method as recited in claim 2, further comprising: providing a second microwave reactor having a source of microwave energy fluidly connected to said first microwave reactor, providing second carbon media in said second reactor; flowing sweep gas from said first microwave reactor, through said second microwave reactor and through said filter. 4. A method as recited in claim 3, further comprising: wherein a portion of said hydrogen sulfide is unreacted; transporting unreacted hydrogen sulfide from said first microwave reactor to said second reactor with said sweep gas; applying microwave energy to said second microwave reactor, and reducing hydrogen sulfide to sulfur and hydrogen in said second reactor. 5. A method as recited in claim 3, further comprising: wherein a portion of nitrogen oxides are unreacted; transporting unreacted nitrogen oxides from said first microwave reactor to said second microwave reactor with said sweep gas; applying microwave energy to said second microwave reactor, and combining nitrogen oxides and said second carbon media to form nitrogen and carbon dioxide in said second reactor. 6. A method to remove hydrogen sulfide from biogas and remove nitrogen oxides from the exhaust of an engine fueled by the biogas comprising: providing a first adsorber having first carbon media configured to remove hydrogen sulfide from a flow of biogas; providing a second adsorber having first carbon media configured to remove nitrogen oxides from the exhaust of an engine fueled by said biogas; providing a first microwave reactor configured to receive first carbon media from said first adsorber and said second adsorber; providing a sweep gas source fluidly connected to said first microwave reactor; wherein sweep gas flows from said sweep gas source through said first microwave reactor; combining first carbon media from said first adsorber with first carbon media from said second adsorber in said first microwave reactor; applying microwave energy to said first microwave reactor to remove hydrogen sulfide and nitrogen oxides from said first carbon media; wherein said nitrogen oxides combine with hydrogen sulfide in said first microwave reactor to form nitrogen, water and sulfur; transporting nitrogen, water and sulfur from said first microwave reactor in said sweep gas; and transporting said first carbon media from said first microwave reactor to said first adsorber and said second adsorber. 7. A method as recited in claim 6, further comprising: providing a second microwave reactor fluidly connected to said first microwave reactor, positioning a second carbon media in said second microwave reactor; providing a filter fluidly connected to said second reactor; wherein sweep gas flows from said sweep gas source, through said first microwave reactor, through said second microwave reactor and through said filter; transporting nitrogen, water and sulfur by said sweep gas from said first microwave reactor to said second reactor; transporting nitrogen, water and sulfur by said sweep gas from said second reactor to said filter; and removing sulfur in said filter. 8. A method as recited in claim 7, further comprising: wherein a portion of said hydrogen sulfide is unreacted; transporting unreacted hydrogen sulfide from said first microwave reactor to said second microwave reactor with said sweep gas; applying microwave energy to said second microwave reactor, and reducing hydrogen sulfide to sulfur and hydrogen in said second microwave reactor. 9. A method as recited in claim 7, further comprising: wherein a portion of nitrogen oxides are unreacted; transporting unreacted nitrogen oxides from said first microwave reactor to said second microwave reactor with said sweep gas; applying microwave energy to said second microwave reactor, and combining nitrogen oxides and said second carbon media to nitrogen and carbon dioxide in said second reactor. 10. A method as recited in claim 6, further comprising positioning a heat exchanger between said engine and said exhaust adsorber.