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Bryan A. ReedRising Senior: Manchester-Essex Regional High School
NEB Summer Internship: Weigele LabJune 23-Aug 15, 2008
Testing Microbial Fuel Cell Parameters:
Composition, Electrolyte, External Load, and Configuration.
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
biomass electricity
The goal
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Create alternative to “baseline” off-grid lighting technologies
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
From the International Finance Corporation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary 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
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Electric Lighting
Fuel-Based Lighting
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
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary 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.
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Core Technology: Microbial Fuel Cell (MFC)
2. Electrolyte
1. Anode
1. Anode: transfer of electrons to anode from electron donors is catalyzed by bacteria2. Electrolyte: transfer of protons (H+) to cathode3. Cathode: reduction of oxygen to form water (H2O): 4H+ + O2 + 4e- H2O
3. Cathode
A combination of cellulolytic and anode reducing bacteria couples oxidation of biomass to electrical power generation.
Biomass + bacteria H2O + CO2 + electricity
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Lab scale MFC
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary 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=V2/R
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Prior Data
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
How does an external load (resistance) affect power output?
• Greater load (more resistance) = less oxidizing anode
• Lower load (less resistance) = more oxidizing anode
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Voltages Obtained Under Varying Resistances
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary 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
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Testing Anode and Medium Composition
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Testing Anode and Medium Composition
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Can we substitute the membrane electrolyte?
• Cation exchange membrane is CMI-7000S• CMI-7000S is $150/m2
•Tyvek is $0.26/m2
•Tyvek is a microporous material (Gore-tex for your house)
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Power obtained without membrane electrolyte
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Repeatability?
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Repeatability?
• Looks like negative results are non-result
• Positive result is still positive result
• Potential leakage of O2 into anode compartment
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Thank you!
Peter Weigele
Harriet Strimpel
Don Comb
( and OGL for seawater)
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Just how much energy is in biomass?
1 watt = 1 joule/second1 watt hour = 3600 joules1 watt hour = 3.413 Btu1 Btu = 1055 joules
1 lb. agricultural residue = 4,300 - 7,300 BtuOr 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 106 joules, or roughly 1.9 kWh
August 5, 2008 Bryan A. Reed- NEB Summer InternSummary Presentation
Electric genes: biological basis for anode reduction by Shewanella
Fe3+
Fe3+
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