Sophmore year microbial fuel cell project. Performed at Clemson University under Dr. Caye Drapcho.

1. Microbial Fuel Cell
Sade Adewale, Nick Balfe, Reece Wilber, and Sarah Van Brunt
Dr. Caye Drapcho
Fundamentals of Biosystems Engineering 2120

2. What is a biological battery?
● A biological reactor that captures electrons released during microbial respiration
● Two chambers, an anode and a cathode
● C6H12O6 + 6H2O 6CO2 + 24H + 24e- Oxidation of Glucose
● 24e- +6O2 + 24H+ 12H2O Reduction of Oxygen
● C6H12O6 +6O2 6CO2 + 6H2O Overall Cellular Respiration
http://www.h-
tec.com/en/education/technology

3. http://illumin.usc.edu/134/microbial-fuel-cells-generating-power-
from-waste/

4. Types of Microbial Fuel Cells
● Two Chamber MFC
○ Aqueous anode and aqueous cathode
● Single Chamber MFC
○ Aqueous anode chamber with air cathode
● Sediment MFS
○ Anode in anaerobic sediment environment and cathode in aerobic water or air environment
http://www.genomenviron.or
g/Research/MFC.html
http://www.engr.psu.edu/ce/enve/loga
n/bioenergy/mfc_photos.htm
http://sbi.oregonstate.edu/news/2009
01.htm

5. Engineering Design Process

6. Recognize the Problem
● Find a means to produce
electrical power sustainably
○ Attempt to produce 1 Watt/Meter
Cubed of power

7. Define the Problem
● Governing Equations
○ Ohm’s Law: Voltage = Current * Resistance
○ Power = Current * Voltage
● Process Goals
○ Implement a biological battery to capture electrons from microbial respiration
○ Utilize culture found in Clemson University Partitioned Aquaculture System
http://www.cgiar.org/consortium-news/women-in-small-scale-
aquaculture/

8. Define the Problem Continued...
● Structural Goals
○ 75% biodegradable, 25% other materials
○ Protect electrical equipment
○ Cannot exceed 20 dollars
● Mechanical Goals
○ Create a complete electrical circuit

9. Research
● Read articles
○ Varying membranes article was not so useful
○ The article on MFCs for performance characterization and capacity improvement informed on the
basic function of microbial fuel cells and investigated the conditions under which MFCs worked
most efficiently based on varying sediments and soils, thermal limits, and electricity production
over time.
● Looked at multiple designs to brainstorm
○ Article on membranes did not apply to sediment design
● Accounted for price of inorganic or not found materials

10. CAD Designs
Sketch of design

11. CAD Design (Side View)
Autocad rendered drawing of MFC

12. CAD Design (Top View)
Top view of MFC in the Partitioned Aquaculture system

13. Design Build
● Bamboo stalk
○ Durable, fully biodegradable
● Wire screen to hold crushed graphite
○ Zipties to hold anode and cathode together
○ 106.66 g anode and 105.77 g cathode (dry
weight)
● Potentiometer to represent a resistance
● Tupperware
○ Protect potentiometer
○ Drilled holes to feed wires

14. Initial Polarization Data
Table 1.1 Range of different resistance values and resulting voltage used to
find polarization curve.

15. Initial Polarization Curve
Figure 1.1 The polarization curve used to determine the MCF’s internal resistance.

16. Initial Power Curve
Figure 1.2 Power produced from initial polarization data

17. Battery Data
Temperature (Celcius) Voltage (Volts)
18.4 0.012
18.4 0.007
20.2 0.018
20.6 0.012
17.3 0.018
14.5 0.070
14.5 0.08
20.6 0.104
Table 2.2 Temperature and voltage data collected over several days.

18. Voltage in relation to Temperature
Figure 3.3 Voltage graphed depending on temperature

19. Power
● Power Density
○ The power produced per anode
volume of sediment MFC designs
○ Power Density = Current * Voltage /
Anode Volume
● 55761.5 W/m^3
● 2.28 Watts produced with our
design

20. Conclusion
● Design proved durable
○ Heavy rain, wind, temperature flux
● Succeeded in achieving 1 Watt of
power

21. Future Work
● Increased surface area in anode and cathode
● Stronger support
○ MFC leaned against the aquaculture barrier
● Remove excess wire
● Use non petroleum-based materials
○ Screen and zip ties
● Implement in warmer temperatures
○ Increases microbial activity