1. Bryan A. Reed Rising Senior : Manchester-Essex Regional High School NEB Summer Internship: Weigele Lab June 23-Aug 15, 2008 Testing Microbial Fuel Cell Parameters: Composition, Electrolyte, External Load, and Configuration.

2. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation biomass electricity The goal

3. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Create alternative to “baseline” off-grid lighting technologies From the International Finance Corporation

4. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Replace inefficient lighting with an LED powered by a Personal Bioreactor From the International Finance Corporation, Photos: Evan Mills © Shoe sellers’ stalls in Tanzania open flame lighting 1-Watt white LED

5. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Source: Evan Mills, International Association of Energy Efficient Lighting and Lawrence Berkeley National Laboratory $38 Billion $185 Billion Global Annual Spending on Lighting From the International Finance Corporation Fuel-based lighting is an $38 billion market

6. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Biological basis of a microbial fuel cell Bacteria can respire (breathe) to insoluble electron acceptors (metal-oxide minerals) in natural anaerobic environments “Exocellular” respiration (transferring electrons out of the cell) yields more ATP and NADH per unit of substrate utilized than fermentation to ethanol, lactate, or acetate. Fuel cell anode material can substitute for native insoluble electron acceptors.

7. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Core Technology: Microbial Fuel Cell (MFC) 2. Electrolyte 1. Anode 1. Anode: transfer of electrons to anode from electron donors is catalyzed by bacteria 2. Electrolyte: transfer of protons (H + ) to cathode 3. Cathode: reduction of oxygen to form water (H 2 O): 4H + + O 2 + 4e -  H 2 O 3. Cathode A combination of cellulolytic and anode reducing bacteria couples oxidation of biomass to electrical power generation. Biomass + bacteria  H 2 O + CO 2 + electricity

8. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Lab scale MFC

9. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Protocol 1:100 dilution of overnight culture of Shewanella oneidensis MR-1 Rich broth or basal medium supplemented with 30 mM sodium lactate and 0.01% SDS Fuel cell attached to external load (an electronic resistor) Voltage measured using an analog-digital converter interfaced to a PC Data collected over time, imported and charted in Microsoft Excel Power calculated by: P=V 2 /R

10. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Prior Data

11. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation How does an external load (resistance) affect power output? Greater load (more resistance) = less oxidizing anode Lower load (less resistance) = more oxidizing anode

12. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation

13. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation

14. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Voltages Obtained Under Varying Resistances

15. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation

16. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Can we obtain power with different anode materials and microbial media? Tested carbon versus graphite felts Tested anode pretreatment (nitric acid soak) Tested basal mineral and seawater based media

17. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Testing Anode and Medium Composition

18. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Testing Anode and Medium Composition

19. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Can we substitute the membrane electrolyte? Cation exchange membrane is CMI-7000S CMI-7000S is $150/m 2 Tyvek is $0.26/m 2 Tyvek is a microporous material (Gore-tex for your house)

20. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation

21. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Power obtained without membrane electrolyte

22. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Repeatability?

23. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation

24. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Repeatability? Looks like negative results are non-result Positive result is still positive result Potential leakage of O 2 into anode compartment

25. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Thank you! Peter Weigele Harriet Strimpel Don Comb ( and OGL for seawater)

26. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation

27. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Just how much energy is in biomass? 1 watt = 1 joule/second 1 watt hour = 3600 joules 1 watt hour = 3.413 Btu 1 Btu = 1055 joules 1 lb. agricultural residue = 4,300 - 7,300 Btu Or roughly 1.26 to 2.14 kWh, equivalent to the energy required to light between 12 and 21 100-Watt bulbs for one hour, or a 1 watt LED for between 52 and 89 days. 1 lb. switchgrass has 6.8 x 10 6 joules, or roughly 1.9 kWh

28. August 5, 2008Bryan A. Reed- NEB Summer Intern Summary Presentation Electric genes: biological basis for anode reduction by Shewanella Fe 3+