US 2010/0143209 A1 · MICROWAVE INDUCED DESTRUCTION OF IMPURITIES FROM BIOGAS AND NITROGEN OXIDES FROM ENGINE EXHAUST

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.

Claims14

Dependent claims

An apparatus for decomposing hydrogen sulfide and nitrogen oxides adsorbed in carbon media, comprising:

a first microwave reactor having a source of microwave energy;
wherein said first microwave reactor is configured to receive a first carbon media containing hydrogen sulfide and nitrogen oxides;
a source of sweep gas connected to said first microwave reactor;
wherein sweep gas flows from said sweep gas source through said first microwave reactor;
wherein hydrogen sulfide and nitrogen oxides are desorbed from said first carbon media in said first microwave reactor when exposed to microwave energy;
wherein said nitrogen oxides react with hydrogen sulfide when exposed to microwave energy to form nitrogen, water and sulfur;
and
wherein nitrogen, water and sulfur are removed from said first microwave reactor in said sweep gas.

5 more elements

An apparatus to remove hydrogen sulfide from biogas and remove nitrogen oxides from the exhaust of an engine fueled by the biogas comprising:

a first adsorber having first carbon media configured to remove hydrogen sulfide from a flow of biogas;
a second adsorber having first carbon media configured to remove nitrogen oxides from the exhaust of an engine fueled by said biogas;
a first microwave reactor configured to receive first carbon media from said first adsorber and said second adsorber;
wherein said first microwave reactor has a source of microwave energy;
a source of sweep gas fluidly connected to said first microwave reactor;
wherein sweep gas flows from said sweep gas source through said first microwave reactor;
wherein hydrogen sulfide and nitrogen oxides are desorbed from said first carbon media in said first microwave reactor when exposed to microwave energy;
wherein said nitrogen oxides react with hydrogen sulfide when exposed to microwave energy in said first microwave reactor to form nitrogen, water and sulfur;
and
wherein said nitrogen, water and sulfur flow from said first microwave reactor in said sweep gas.

7 more elements

Dependencies are inferred from the claim text.

Microwave induced destruction of impurities from biogas and nitrogen oxides from engine exhaust

Life of this patent

Microwave induced destruction of impurities from biogas and nitrogen oxides from engine exhaust

Life of this patent

Abstract

Claims14