2. HISTORY OF FUEL CELLS
The first fuel cells were INVENTED by Sir WILLIAm GROVe in 1838.
The invention of the hydrogen–oxygen fuel cell for
COMMERCIAL USE BY FRANCIs THOmAs BACON in 1932.
3. WHAT IS A FUEL CELL ?
A Fuel Cell is an electrochemical device that combines hydrogen and
oxygen to produce electricity, with water and heat as its by-product.
It is an energy conversion device or electricity generator.
It is an example for a primary cell.
This is capable of supplying current as long as it is provided with the supply of
reactants.
GENERAL EQUATION :
FUEL + OXYGEN →OXIDATION PRODUCTS + ELECTRICITY
(OXIDANT)
5. HOW DOES A FUEL CELL WORK
It operates similarly to a battery, but it does not run down nor does it require
recharging
As long as fuel is supplied, a Fuel Cell will produce both energy and HEAT
A Fuel Cell consists of two catalyst coated electrodes surrounding an
electrolyte
One electrode is an anode and the other is a cathode
The process begins when Hydrogen molecules enter the anode
The catalyst coating separates hydrogen’s negatively charged electrons
from the positively charged protons.
6. HOW DOES A FUEL
CELL WORK
The electrolyte allows the protons to pass through to the cathode, but not
the electrons
Instead the electrons are directed through an external circuit which
creates electrical current
While the electrons pass through the external circuit, oxygen molecules
pass through the cathode
There the oxygen and the protons combine with the electrons after they
have passed through the external circuit
7. HOW DOES A FUEL CELL WORK ???
When the oxygen and the protons
combine with the electrons it
produces water and heat.
Picture of fuel cell
8. mOsT ImPORTANT CHARACTeRIsTICs
High efficiency
Low emission levels
Low noise levels
Fuel cells are free from vibration, heat transfer and
thermal pollution
10. HYDROEN-OXYGEN FUEL CELL(H2-O2)
A common type of fuel cell based on the combustion of hydrogen gas.
Equation : 2H2 + O2 2H2O
(g) (g) (l)
11.
12. consists two electrodes
made up of graphite
catalyst platinum or metal oxide
placed in aqueous solution (KOH or NAOH)
H2 Gas evolves in anode
O2 Gas evolve in cathod
REACTION
AT Anode
H2 + 2OH− → 2H2O + 2e−
(g) (aq) (L)
AT CATHOD
O2(g) + 2H2O + 4e− → 4OH
(g) (l)
2H2 + O2 → 2H2O
(g) (g) (L)
13. THE Standard EMF Of H2 – O2 CELLS
E° = E°(cathode) - E°(anode)
14. USES OF H2 – O2 CELLS
• used in space craft because of their high
efficiency, lightness
• used in submarines or other military vehicles
• used as the primary source of electrical energy
on the Apollo moon flights. Approximately 200
kg of fuel is sufficient for 11 days in space
15. ADVANTAGES OF FUEL CELLS
The energy conversion (chemical into
electrical) is very high by fuel cells (75-82.8%).
H2-O2 fuel cell produces H2O, which is used as
drinking purpose by astronauts
Noise and thermal pollution are low.
Such type of cells never becomes dead,
because of continuous supply of fuel
16. ADVANTAGES OF FUEL
CELLS
Modular and other parts of fuel cells
are exchangeable
Fuels cells having low maintenance
cost
Fuels cells saves fossil fuels.
17. Disadvantages of Fuel Cells
High initial cost.
Large weight and volume of gas-fuel storage
system.
High cost of pure hydrogen.
Life-times of such type of cells are not
accurately known.