microbial fuel cells

1. NEED OF MFC(MICROBIAL
FUEL CELL):
.
•Two very great issues are daunting
scientists today-the fuel crisis and bio
waste disposal
• The answer to both these problems
may be provided by our planet's smallest
creatures : bacteria.
•'Microbial Fuel Cell' (MFC) can help
convert bio-waste into electricity

2. MICROBIAL FUEL CELL:
• Microbial Fuel cell is bio-electrochemical fuel cell where
the anode reaction is controlled by
microorganisms. 'Anode respiratory bacteria' have the
ability to convert bio-waste to electrons.

3. COMPONENTS OF MFC
•Anode compartment
where fuel is oxidized by
bacteria which generates
free electrons and H30+
•A membrane that
separates Anode and
Cathode and allows flow of
H3O+
•An external circuit helps
transfer of electrons from
anode to cathode

4. WORKING PRINCIPLE OF
MFC
• When bacteria are placed in the anode chamber of a specially-
designed fuel cell that is free of oxygen, they attach to an
electrode.
• Because they do not have oxygen, they must transfer the
electrons that they obtain from consumption (oxidation) of their
food somewhere else than to oxygen-- they transfer them to the
electrode.
• In a MFC these electrons therefore go to the anode, while the
counter electrode (the cathode) is exposed to oxygen. At the
cathode the electrons, oxygen and protons combine to form
only water. The two electrodes are at different potentials (about
0.5 V)

5. WORKING DIAGRAM OF MFC
Anode Reaction:
C12H22O11 + 13H2O ---> 12CO2 + 48H+ + 48e-
Cathode Reaction:
4H+ + O2 + 4e-  2H2O

6. POWER DENSITIES AVAILABLE:
• Power densities as high as 1.55 kW/m3 have been
produced using very small (2.5 mL) air-cathode MFCs
• An even higher power density of 2.15 kW/m3 was
generated
• using an even smaller 0.335-mL MFC with a membrane
and
• a ferricyanide solution, by using a disproportionately
sized
• cathode surface area of 1,920 m2/m3 (16 times the area
of
• the anode)

7. SCOPE OF IMPROVEMENT:
• The great advantage of the microbial fuel cell is the direct
conversion of organic waste into electricity.
• In the future, MFC’s may be linked to municipal waste
streams or sources of agricultural and animal waste,
providing a sustainable system for waste treatment and
energy production.
• MFCs are far from making a industrial debut soon. Better
research can definitely speedup this process

8. PROTOYPE