2. 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. As long as fuel
is supplied, the fuel cell will continue to generate power. Since the
conversion of the fuel to energy takes place via an electrochemical process,
not combustion, the process is clean, quiet, and highly efficient-two to three
times more efficient than fuel burning.
3. SAMPLE FOOTER TEXT 20XX 3
TYPES OF FUEL CELLS
Fuel Cells are of the following types:
Proton Exchange Membrane Fuel Cell
Alkaline Fuel Cell
Direct Methanol Fuel Cell
Phosphoric Acid Fuel Cell
Molten Carbonate Fuel Cell
Solid Oxide Fuel Cell
Microbial Fuel Cell
Zinc Air Fuel Cell
4. PROTON EXCHANGE MEMBRANE FUEL
CELL (PEM)
Reactions:
At the Anode:
H2 2H+ + 2e-
At the Cathode:
½ 02 + 2H+ + 2e- H2O
Overall reaction:
H2 + ½ 02 H2O
5. 5
ALKALINE FUEL CELL (AFC)
The alkaline fuel cell (AFC), also known as the Bacon fuel cell after its
British inventor, is one of the most developed fuel cell technologies and is
the cell that flew Man to the Moon.
Reactions:
At Anode:
H2 + 2OH - 2H20 + 2e-
At Cathode:
O2 + 2H20 + 4e- 40H-
6. 6
DIRECT METHANOL FUEL CELL (DMFC)
Direct-methanol fuel cells or DMFCs are a subcategory of proton-
exchange fuel cells in which methanol is used as the fuel.
Reactions:
At Anode
CH3OH + H20 6H+ +6e- +CO2
At Cathode
3/2 02 + 6 H+ +6e- 3 H2O
Overall reaction
CH30H + 3/202 2 H20 + CO2
7. SAMPLE FOOTER TEXT
PHOSPHORIC ACID FUEL CELL (PAFC)
Phosphoric acid fuel cells use liquid phosphoric acid as the electrolyte
and operate at about 450°F.
Reactions:
At the Anode:
H2 2H+ + 2e-
At the Cathode:
½ 02 + 2H+ + 2e- H2O
Overall reaction:
H2 + ½ 02 H2O
8. MOLTEN CARBONATE FUEL CELL
“Molten carbonate fuel cells use an electrolyte composed of a molten
carbonate salt mixture suspended in a porous, chemically inert matrix,
and operate at high temperatures - approximately 600°C.
At the anode:
H2+CO3 H20+CO2+2e-
At the cathode:
½ 02 + CO2 + 2e- CO3
The overall cell reaction:
H2 +1/2 O2 + CO2 H2O +CO2
9. SOLID OXIDE FUEL CELL
The electrochemical reactions occurring within the
cell are:
At the anode:
1/2 02+2e- O
At the cathode:
H2+1/2 0 H2O + 2e-
The overall cell reaction:
½ 02 +H2 H2O
Solid oxide fuel cells use a hard, non-porous ceramic compound as the
electrolyte, and operate at very high temperatures between 500 and 1,000 °C.
10. MICROBIAL FUEL CELL
Microbial fuel cells use the catalytic reaction of microorganisms such as
bacteria to convert virtually any organic material into fuel.
It could be capable of producing over 50% efficiency.
When microorganisms consume a substrate such as sugar in aerobic conditions
they produce carbon dioxide and water. However when oxygen is not present
they produce carbon dioxide, protons and electrons as
C12H22O11 + 13H2O 12CO2 + 48H+ + 48e
MFCs could be installed in wastewater treatment plants. The bacteria would
consume waste material from the water and produce supplementary power for
the plant.
12. ZINC AIR FUEL CELL
In a zinc-air fuel cell, there is a gas diffusion electrode (GDE), a zinc anode
separated by electrolyte, and some form of mechanical separators. The GDE is a
permeable membrane that allows atmospheric oxygen to pass through.
The electrolyte for a ZAFC is a ceramic solid that employs the hydroxyl ion,
OH-, as the charge carrier. ZAFC operates at 700°C.
Anode Reaction:
CH4 +H2O CO2+ 6H+ + 6e- Zn + OH- ZnO + H + e-
Cathode Reaction:
O2 + 2H+ +2e- 2OH- O2+ 4H+ +4e- 2H2O
Overall Cell Reaction:
CH4+202 CO2 +2H2O
14. HYDROGEN FUEL CELL
Produces electricity through a chemical reaction, but without combustion.
Converts hydrogen and oxygen into the water.
2H2 + O2 2H2O
Operates much like a battery, except they don’t require electrical recharging.
Can generate power almost indefinitely, as long as they have fuel to use.
Hydrogen fuel cells (HFCs) are a type of electrochemical cell.
HFCs generate electricity by reduction and oxidation reactions within the cell.
They use three main components, a fuel, an oxidant, and an electrolyte.
HFCs operate like batteries, although they require external fuel.
HFCs is a thermodynamically open system.
HFCs use hydrogen as a fuel, oxygen as an oxidant, a proton exchange
membrane as an electrolyte, and emit only water as waste.
15. HOW THEY WORK? HFC IN VECHILE
The 2015 Toyota Mirai is one of the first hydrogen
fuel cell vehicles to be sold commercially. The Mirai
is based on the Toyota FCV concept car
Honda FCX Clarity, a hydrogen fuel cell
demonstration vehicle introduced in 2008
16. ADVANTAGE
It is readily available.
It doesn’t produce harmful
emissions.
It is environmentally friendly.
It can be used as fuel in rockets.
It is fuel efficient.
It is renewable.
D
DISADVANTAGE
H2 is difficult/expensive to
produce, store and transport.
Fuels cells require pure fuel.
Platinum catalysts are expensive
and rare.
Proton exchange membranes
must be kept moist.
Hydrogen fuel cell stacks are
heavy.