Method and apparatus for converting chemical energy stored in wastewater into electrical energy

• US 10,340,545 B2
• Filed: 11/11/2015
• Issued: 07/02/2019
• Est. Priority Date: 11/11/2015
• Status: Active Grant

• Current Assignee: BioEnergySP, Inc.
• Original Assignee: BioEnergySP, Inc.
• Inventors: Lozano, Jose Luis
• Primary Examiner(s): Rhee, Jane J
• Application Number:
  US14/938,258
• Publication Number:
  US 20170133700A1
• Time in Patent Office: 1,329 Days
• CPC Class Codes: H01M 8/0202 Collectors; Separators, e.g. bipolar separators; Interconnectors
• 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

A method and apparatus is provided for harvesting electricity from a biofilm retained in a zero chamber, no interphase container, the biofilm having a portion supporting aerobic microbial activity and a second portion supporting anaerobic microbial activity, wherein the first and the second portion are in direct physical contact. A power harvester is electrically connected, directly or indirectly, to the second portion of the biofilm.

Claims

1. A method comprising:

(a) forming a biofilm on a substrate exposed to a volume of wastewater having dissolved oxygen, the biofilm having a sufficient thickness to define a gradient between aerobic microorganisms exposed to the wastewater and anaerobic microorganisms proximal to the substrate;

(b) electrically connecting the biofilm to a power harvester, the power harvester being free of an electrical connection to a separate cathode; and

(c) electrically connecting the power harvester to a ground lead.

2. The method of claim 1, further comprising electrically connecting the substrate to the power harvester.

3. The method of claim 1, wherein the ground lead is further electrically connected to at least one of the wastewater and a container retaining the volume of wastewater.

4. The method of claim 1, wherein electrically connecting the biofilm to a power harvester includes electrically connecting the substrate to the power harvester.

5. The method of claim 1, wherein the volume of wastewater is independent of a PEM membrane.

6. The method of claim 1, wherein the volume of wastewater is independent of a catalyst.

7. The method of claim 1, wherein the volume of wastewater is retained in a container, and the container is independent of an interphase for oxygen diffusion.

8. The method of claim 1, wherein the wastewater is organic.

9. The method of claim 1, wherein electrically connecting the biofilm includes electrically connecting a portion of the anaerobic microorganisms to the power harvester.

10. A microbial fuel cell comprising:

(a) a container for retaining a volume of wastewater, the wastewater including dissolved oxygen;

(b) a substrate at least partially submerged in the wastewater, the substrate supporting a biofilm exposed to the volume of organic wastewater, the biofilm having a sufficient thickness to define an electron concentration gradient between microorganisms exposed to the wastewater and microorganisms proximal to the substrate;

(c) a power harvester; and

(d) a first electrical conductor between the power harvester and one of (i) the biofilm and (ii) the substrate, wherein the power harvester is free of an electrical connection to a separate cathode.

11. The microbial fuel cell of claim 10, further comprising a second electrical conductor between the power harvester and a ground.

12. The microbial fuel cell of claim 10, wherein the substrate is conducting.

13. The microbial fuel cell of claim 10, wherein the substrate is non-conducting.

14. The microbial fuel cell of claim 11, wherein the ground is the wastewater.

15. The microbial fuel cell of claim 11, wherein the ground is the container.

16. The microbial fuel cell of claim 10, wherein the container is independent of a proton exchange membrane.

17. The microbial fuel cell of claim 10, wherein the container is independent of a catalyst.

18. The microbial fuel cell of claim 10, wherein the container is independent of an interphase for oxygen diffusion.

19. The microbial fuel cell of claim 10, wherein the container is independent of a membrane compartment.

20. A microbial fuel cell comprising:

(a) a container retaining a volume of wastewater, the container being free of a proton exchange membrane and the wastewater including dissolved oxygen;

(b) a substrate at least partially submerged in the wastewater, the substrate supporting a biofilm exposed to the volume of organic wastewater, the biofilm having a sufficient thickness to define an oxygen concentration gradient between microorganisms exposed to the wastewater and microorganisms proximal to the substrate wherein the gradient is sufficient to generate sufficient free electrons;

(c) a power harvester;

(d) a first electrical conductor between the power harvester and one of (a) the biofilm and (b) the substrate; and

(e) a second electrical conductor between the power harvester and a ground, wherein the power harvester is free of an electrical connection to a separate cathode.

21. The microbial fuel cell of claim 20, wherein the substrate is conducting.

22. The microbial fuel cell of claim 20, wherein the substrate is non-conducting.

23. The microbial fuel cell of claim 20, wherein the ground is the wastewater.

24. The microbial fuel cell of claim 20, wherein the ground is the chamber.

25. The microbial fuel cell of claim 20, wherein the ground is a common electrical ground.

26. The microbial fuel cell of claim 20, wherein the container is independent of a proton exchange membrane.

27. The microbial fuel cell of claim 20, wherein the container is independent of a catalyst.

28. The microbial fuel cell of claim 20, wherein the container is independent of an interphase for oxygen diffusion.

29. The microbial fuel cell of claim 20, wherein the container is independent of a membrane compartment.