2. INTRODUCTION TO FUEL CELL
A fuel cell is a device that converts the chemicalenergy
from a fuel into electricity, water and heat through a
chemical reaction with oxygen.
Fuel cells are different from batteries in that they require
a constant source of fuel and oxygen/air to sustain the
chemical reaction. Fuel cells can produce electricity
continually for as long as these inputs are supplied.
The first fuel cells were invented in 1838. The first
commercial use of fuel cells came more than a century
later in NASA space programs.
3. PARTS OF A FUEL CELL
Anode:
Negative post of the fuelcell.
Conducts the electrons that are freed from the hydrogen molecules so that
they can be used in an external circuit.
Etched channels disperse hydrogen gas over the surface of catalyst.
Cathode:
Positive post of the fuelcell
Etched channels distribute oxygen to the surface of thecatalyst.
Conducts electrons back from the external circuit to thecatalyst
Recombine with the hydrogen ions and oxygen to form water.
Electrolyte:
Proton exchange membrane.
Specially treated material, only conducts positively chargedions.
Membrane blocks electrons.
Catalyst:
Special material that facilitates reaction of oxygen andhydrogen
Usually platinum powder very thinly coated onto carbon paper orcloth.
Rough & porous maximizes surface area exposed to hydrogen or oxygen
The platinum-coated side of the catalyst faces the PEM.
4. HYDROGEN FUEL CELL
2
ions and two electrons (e-)
On the other side, oxygen gas is forced
through the catalyst forms two oxygen atoms,
each with a strong negative charge.
This attracts the H+ towards it.
The fusion results in, heat and electricity.
The end product is water vapors and
electrons, that produce electricity.
It splits the H molecule into two H+
Anode reaction:
H2 = 2H+ + 2e-
Cathode reaction:
O2 + 2H+ = 2H2O
5. HYDROGEN FUEL CELL IN AUTO MOBILE
Heat and electrical energy is formed after the fusion of
electrons. Therefore, electrical energy is used to drive the
vehicle and we get water (H2O) as our exhaust. The heat
energy converts water into water vapor and thus our
exhaust from the vehicle is in the form of water vapor
which ultimately has no effect to the environment.
Thus, no pollution is created using this technology.
6. SOMETHING TO KNOW
The 1966 GM Electrovan
It is credited with being the
first hydrogen fuel cell car ever
produced. Though fuel cells have
been around since the early 1800's,
General Motors was the first to use a
fuel cell to power the wheels of a
vehicle.
7. TERMINOLOGY OF HYDROGEN FUEL CELL IN AUTOMOBILE
Fuel cells: Afuel cell is a device that converts the chemical energy into
electrical energy, water and heat through chemical reactions.
Hydrogen tank:Acylinder tank used for storing hydrogen in a car.
Traction inverter module: The traction inverter module is used to
convert supplied energy as efficiently as possible and make itavailable
to the drive motors in a suitable way.
Turbo compressor: A dynamic-type compressor is used forthe
compression and injection of gases (oxygen).
Transaxle: An automotive part that perform gear changing function
and power splitting ability.
10. HYDROGEN STORAGE TECHNOLOGIES
Physical storage of H2
•Compressed •Cryogenically liquefied
Chemical storage of hydrogen
•Sodium borohydride •Alkali metal hydrides
New emerging methods
•Amminex tablets •Solar Zinc production
11. COMPARISON BASED ON CALORIFIC VALUE:
For hydrogen:
Higher calorific value: 141,790 kJ/kg
Lower calorific value: 121,000 kJ/kg
For petrol:
Calorific value: 48,000 kJ/kg
Heat generated from the hydrogen is more than that of petrol
or other gasoline fuels as the calorific value of hydrogen is
more. Thus, the power developed is more in vehicles
running on hydrogen fuel cells.
12. FUTURE SCOPE
The technology should be made cost effective.
Developing more safety features to the onboard hydrogen tank
and also at refilling stations by making the use of ‘Auto-
locking of supply valves by using hydrogen detector.’
In this technique, if the hydrogen is leaked from the cylinder
or supply line then hydrogen will be detected by the sensor
provided to it by sensing the tlv (threshold limit value) of
hydrogen.
When the gas is detected, the supply valves from the hydrogen
tank are closed. Thus, hydrogen gas leaking is thus avoided.
The other technique is to splash the water where the hydrogen
gas is leaked. But for this, there will be separate water storing
facility required. Thus, hazards expected from hydrogen gas
leaking are thus avoided
13. LIMITATIONS
For instance, you don't have a hydrogen pipeline coming
to your house, and you can't pull up to a hydrogen pump
at your local gas station.
Hydrogen is difficult to store and distribute, so it would
be much more convenient if fuel cells could use fuels
that are more readily available.
Technology is currently expensive.
14. CONCLUSION
Thus, it can be said that there will be a bright future if this
hydrogen fuel cell is put up to use in all vehicles by properly
considering the safety matter first.
And if this eco-friendly technology is used, the rate of
pollution is surely going to come down.
It is not only eco-friendly but, also serves to be a great fuel
source. Since the conventional sources of fuel may not prove
to be sufficient, there arises a need to develop a new
alternative source of energy. Although there are a few
problems related with the storage of hydrogen gas, which
might be overcome as the technology develops further.
“Hydrogen holds the great promise to meet our future energy
needs concerned with our environment.”
