Multi-electrode microbial fuel cells and fuel cell systems and bioreactors with dynamically configurable fluidics

• US 8,518,566 B2
• Filed: 03/18/2010
• Issued: 08/27/2013
• Est. Priority Date: 03/18/2009
• Status: Active Grant

• Current Assignee: Oakbio, Inc.
• Original Assignee: Oakbio, Inc.
• Inventors: Sefton, Brian
• Primary Examiner(s): Cano, Milton I
• Assistant Examiner(s): THOMAS, BRENT C
• Application Number:
  US12/726,980
• Publication Number:
  US 20100239920A1
• Time in Patent Office: 1,258 Days
• Field of Search: 429/2, 429/401
• US Class Current: 429/2
• CPC Class Codes: H01M 8/16 Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Microbial fuel cells including multiple electrodes, and systems of such fuel cells, are provided. An exemplary fuel cell includes a population of exoelectrogenic microbes and at least two anodes in an anode chamber, and a cathode in a cathode chamber. A path exists between the chambers for conducting hydrogen ions and each anode is connected to the cathode by a separate external circuit. Electrical output from the fuel cell is maximized by optimizing the microbe population, achieved by dynamically controlling the sub-populations at each of the multiple anodes. Systems comprising multiple such fuel cells connected by a dynamically reconfigurable fluidics system provide further optimization.

Claims

1. A method comprising:

feeding a nutrient stream to a microbe population in a first chamber of a microbial fuel cell,

the first chamber including

a first electrode connected by a first external electrical circuit to a counter-electrode in a second chamber of the microbial fuel cell and

a second electrode connected by a second external electrical circuit to the counter-electrode, and

the nutrient stream encountering the first electrode before the second electrode as the nutrient stream flows through the first chamber; and

inhibiting further microbial growth in a sub-population of the microbial population associated with the first electrode while promoting growth of a second sub-population of the microbial population associated with the second electrode by raising a resistance of the first external electrical circuit while maintaining the second external electrical circuit.

2. The method of claim 1 wherein raising the resistance of the first external electrical circuit comprises breaking the first external electrical circuit.

3. The method of claim 1 wherein the sub-populations are different.

4. The method of claim 1 wherein the nutrient stream comprises waste water.

5. The method of claim 1 wherein the microbe population includes exoelectrogenic microbes.

6. The method of claim 1 wherein the microbe population does not include exoelectrogenic microbes and the first chamber includes a mediator.

7. The method of claim 1 further comprising monitoring a condition within the first chamber.

8. The method of claim 7 wherein the condition comprises a voltage between the first electrode and the counter-electrode.

9. The method of claim 1 wherein raising the resistance of the first external electrical circuit comprises increasing a load on the first external electrical circuit.

10. The method of claim 3 wherein the first and second sub-populations comprise the same microbes in different metabolic states.

11. The method of claim 1 wherein a semi-permeable membrane separates the first and second chambers of the microbial fuel cell.