microbial fuel cell

Clean

energy :B a c t e r i a j o i n

f o r c e s

BYAmr Mohammed Atef Khedr

Under Supervision

Prof Dr / Fatma El-Zamik Prof Dr/ Gamal El Din Mostafa

Prof Dr / Howaida Labeeb

WHAT IS A MICROBIAL FUEL CELL??

A microbial fuel cell (MFC) is a bio-electrochemical system that converts the chemical energy in the organic compounds/renewable energy sources to electrical energy/bio-electrical energy through microbial catalysis at the anode.

This process is becoming attractive and alternative methodology for generation of electricity.

Why we need mfc (microbial fuel

cell)….???Microbial fuel cells (MFCs) represent a completely new method of renewable energy recovery: the direct conversion of organic matter to electricity using bacteria.

An approximate estimate of global wastewater production is about 1,500 km3 per day.

It is a good way to use waste water converting into electricity.

The gains to be made are that MFCs are a very cleanand efficient method of energy production and theyalso treat waste generated in daily life so use of MFCsare like “Hitting two birds with one stone”.

1. Anode chamber,

2. Cathode chamber,

3. membrane that seperates the anode and

cathode chamber(like potassium nitrate base

membrane or salt type membrane),

4. Electrodes(cu or al),

5. copper wire that joins electrodes,

6. waste water that contain organic materials.

How Does It Work????• Organic matter is oxidized by bacteria creating an electric potential and generating Co2, protons and electrons.•Electrons are transferred to the cathode compartment through an external electric circuit, while protons are transferred to the cathode compartment through the membrane.• Electrons and protons are consumed in the cathode compartment, combining with oxygen to form water.

Anode reaction : C12H22O11 + 13H2O ---> 12CO2 + 48H+ + 48e-

Cathode reaction : 4H+ + O2 + 4e- 2H2O

Types of MFC

Typically run in Batch Mode in

medium like Glucose or Acetate

to generate electricity.

Currently used in laboratories

only.

Exists in various shapes like

cylindrical, rectangular,

miniature, Upflow with

cylindrical, U-shaped cathode.

Various microbes used in MFCs

Electro active Bacteria

Other species include :

•Shewanella putrefaciens

•Aeromonas hydrophila

•Pseudomonas species

Some bacteria, which have pili on their external membrane, are able to transfer their electron production via these pili.

Microbe Substrate Anode Voltage

E coli Glucose Pt- C-cloth 625mV

Bacillus

subtilis

Glucose Vitreous

Carbon

640mV

E coli Acetate Graphite

felt

250mV

Pseudomonas

methanica

Methane Pt-black 550mV

Proteus

vulgaris

Sucrose Carbon rod 350mV

1.Power generation2. Biosensor3. Biogas4. As alternative of waste treatment:-5. Bio-fuel Applications: Gases

Bacteria would consume waste material from the water

and produce supplementary power for the plant. The

gains to be made from doing this are that MFCs are a

very clean and efficient method of energy production.

Chemical processing wastewater and designed synthetic

wastewater have been used to produce bioelectricity in

dual- and single-chamber mediatorless MFCs (non-coated

graphite electrodes) apart from wastewater treatment.

Since the current generated from a microbial fuel cell

is directly proportional to the energy content of

wastewater used as the fuel, an MFC can be used to

measure the solute concentration of wastewater .

The strength of wastewater is commonly evaluated as

biochemical oxygen demand (BOD) values.

An MFC-type BOD sensor can be used to measure real-

time BOD values.

Biohydrogen:• Protons and electrons produced at the anode

are combined at the cathode to form Hydrogen.

•The hydrogen can be accumulated and stored

for later use .

Modifying the anodes of a MFC using nanofabrication

techniques can result in increase of the current density

output of the MFC.

Characterizing the Nanomodified anodes using

microscopy can result in increase in efficiency of

MFCs.

Growing gold, iron, and nickel Nanoparticles (NPs) and

Walled Carbon Nanotubes(MWCNTs) on anode plate

will increase the attracting power of anode towards

electrons and hence will result in increase in efficiency

of MFC.

Carbon nanotubes

Performance Enhancement of MFC

Nanoscale: 1x 10-9m = 1nm.

A hair is ≈ 10 μm (10,000 larger) Nanostructures are thought to improve e-

transfer from bacteria to Anode.