Electromethanogenic reactor and processes for methane production

• US 8,440,438 B2
• Filed: 06/22/2009
• Issued: 05/14/2013
• Est. Priority Date: 06/20/2008
• Status: Active Grant

• Current Assignee: Penn State Research Foundation
• Original Assignee: Penn State Research Foundation
• Inventors: Cheng, Shaoan, Logan, Bruce
• Primary Examiner(s): Ford, Allison
• Assistant Examiner(s): FERNANDEZ, SUSAN EMILY
• Application Number:
  US12/488,951
• Publication Number:
  US 20090317882A1
• Time in Patent Office: 1,422 Days
• Field of Search: None
• US Class Current: 435/167
• CPC Class Codes: C12M 21/04 for producing gas, e.g. biogas digesters for manure with production of biogas A01C3/028, biological treatment of water, waste water or sewage C02F3/00, C02F11/02, preparation of natural gas or syngas C10L3/06, C10L3/10
• CPC Class Codes: C12M 23/34 Internal compartments or partitions
• CPC Class Codes: C12M 35/02 Electrical or electromagnetic means, e.g. for electroporation or for cell fusion
• CPC Class Codes: C12N 13/00 Treatment of microorganisms or enzymes with electrical or wave energy, e.g. magnetism, sonic waves
• CPC Class Codes: C12P 39/00 Processes involving microorganisms of different genera in the same process, simultaneously
• CPC Class Codes: C12P 5/023 Methane
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: C25B 11/04 characterised by the material
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight

Abstract

Increasing competition for fossil fuels, and the need to avoid release carbon dioxide from combustion of these fuels requires development of new and sustainable approaches for energy production and carbon capture. Biological processes for producing methane gas and capturing carbon from carbon dioxide are provided according to embodiments of the present invention which include providing an electromethanogenic reactor having an anode, a cathode and a plurality of methanogenic microorganisms disposed on the cathode. Electrons and carbon dioxide are provided to the plurality of methanogenic microorganisms disposed on the cathode. The methanogenic microorganisms reduce the carbon dioxide to produce methane gas, even in the absence of hydrogen and/or organic carbon sources.

Claims

1. A biological process for producing methane gas comprising:

providing an electromethanogenic reactor having an anode, a cathode, and a plurality of methanogenic microorganisms disposed on the cathode, the plurality of methanogenic microorganisms comprising at least two phylotypes of methanogenic microorganisms of the Archaea domain;

providing electrons to the plurality of methanogenic microorganisms disposed on the cathode, wherein no mediator of electron transfer is present in the electromethanogenic reactor; and

providing carbon dioxide to the plurality of methanogenic microorganisms and substantially excluding hydrogen from the electromethanogenic reactor such that hydrogen gas does not contribute to methane production by the methanogenic microorganisms, whereby the methanogenic microorganisms reduce the carbon dioxide in the absence of hydrogen gas to produce methane gas.

2. The process of claim 1, wherein a power source is in electrical communication with the reactor to enhance a potential between the anode and the cathode.

3. The process of claim 1, wherein electrons provided to the plurality of methanogenic microorganisms comprises electrons transferred to the anode by a plurality of exoelectrogenic bacteria.

4. The process of claim 2, wherein the power source is selected from the group consisting of:

wind-generated power, solar power, a microbial fuel cell, a DC power source, an electrochemical cell, and a combination of two or more thereof.

5. The process of claim 1, further comprising increasing methane gas production rate by adding an additional voltage to the cathode.

6. The process of claim 1 wherein the electromethanogenic reactor comprises an anode chamber and a cathode chamber.

7. The process of claim 6 wherein no organic carbon source is added to the cathode chamber.

8. The process of claim 6 wherein no hydrogen is added to the cathode chamber.

9. The process of claim 1, wherein substantially no organic carbon source is available to the plurality of methanogenic microorganisms.

10. The process of claim 1, wherein metal catalysts are substantially excluded from the cathode.