FUEL CELL AND IT’S
A Presentation By:-
Prof. P.N. Dange
Schematics of reactant flow in a MCFC
WHAT IS A FUEL CELL?
It is a galvanic cell or electrochemical power
it generates electrical energy with water and heat
as its by-product
both the reactants and the products are liquids or
CONSTRUCTION & WORKING OF A FUEL CELL
Has two electrodes, anode and
An electrolyte, which carries
electrically charged particles
from one electrode to the other
A catalyst, which speeds the
reactions at the electrodes.
Overall reaction is split into two
partial reactions : oxidation and
Process begins when Hydrogen molecules enter anode
Catalyst coating separates hydrogen’s negatively charged electrons
from the positively charged protons
Electrolyte allows protons to pass through to cathode, but not
Instead electrons are directed through an external circuit which
creates electrical current
Oxygen molecules pass through cathode
Oxygen and protons combine with electrons after they have
passed through the external circuit
Oxygen and protons combine with electrons to produce water and
CONSTRUCTION & WORKING OF A FUEL CELL
TYPES OF FUEL CELL
1] Phosphoric acid fuel cell (PAFC)
Electrolyte is phosphoric acid
Efficiency is 40 to 80 percent
Operating temperature –
150 to 200oC (300 to 400o F)
Output - up to 200 kW
PAFCs tolerate a carbon
monoxide concentration of
about 1.5 percent
2] Alkaline fuel cell (AFC)
Operate on compressed
hydrogen and oxygen.
Generally use solution of
potassium hydroxide (chemically
KOH) in water as their
Efficiency is about 70 percent
Operating temperature is 150
to 200o C, (about 300 to 400o F)
Cell output ranges from 300
W to 5 kW.
3] Proton-exchange-membrane fuel cell (PEMFC)
Work with a polymer electrolyte in
the form of a thin, permeable sheet
Efficiency is about 40 to 50 percent
Operating temperature is about 80o C
(about 175o F)
Cell outputs generally range from 50 to
Anode (oxidation): H2 2H+ + 2e-
Cathode (reduction): ½ O2 2H+ +2e- H2O
Overall : H2 + ½ O2 H2O
4] Direct-methanol fuel cell (DMFC)
Specific content of
chemical energy of about
are in the range
Power outputs between
25 watts and 5 kilowatts
Anode (oxidation) : CH3OH + 60H- 5H2O + 6e- + CO2
Cathode (reduction) : 3/2 O2 + 3H2O + 6e- 6OH-
Overall : CH3OH + 3/2 O2 CO2 + 2H2O
5] Molten-carbonate fuel cell (MCFC)
compounds of salt (like sodium or
(chemically CO3) as the electrolyte
Efficiency ranges from 60 to
Operating temperature is about
650o C (1,200 o F)
Output upto 2 megawatts (MW)
Overall reaction : CO + ½O2 CO2
Oxidation reaction : CO + CO3
2- 2CO2 + 2e-
Reduction reaction : ½O2 + CO2 + 2e- CO3
6] Solid-oxide fuel cell (SOFC)
Use a hard, ceramic compound
of metal (like calcium or
zirconium) oxides (chemically, O2)
Efficiency is about 60 percent
Operating temperatures are
about 1,000o C (about 1,800 o F)
Cells output is up to 100 kW
Reduction reaction : ½O2 + 2H+ + 2e- H2O
Oxidation reaction : H2 2H+ + 2e-
Overall reaction : H2 + ½O2 H2O
Stationary Power Stations
Transportation : All major automakers are working to
commercialize a fuel cell car.Automakers and experts speculate
that a fuel cell vehicle will be commercialized by 2010.
Stationary Power Stations : Over 2,500 fuel cell systems have
been installed all over the world in hospitals, nursing homes,
hotels, office buildings, schools and utility power plants.
Telecommunications : Due to computers, the Internet and
sophisticated communication networks there is a need for an
incredibly reliable power source. Fuel Cells have been proven to
be 99.999% reliable
Micro Power :
• Consumer electronics could gain drastically longer
battery power with Fuel Cell technology.
• Cell phones can be powered for 30 days without
• Laptops can be powered for 20 hours without
Physical Security : Both central station power generation and
long distance, high voltage power grids can be terrorist targets in
an attempt to cripple our energy infrastructure.
Reliability : Properly configured fuel cells would result in less
than one minute of down time in a six year period. U.S.
businesses lose $29 Billion a year from computer failures due to
Efficiency : Because no fuel is burned to make energy, fuel cells
are fundamentally more efficient than combustion systems.
Environmental Benefits : Fuels cells can reduce air pollution
today and offer the possibility of eliminating pollution in the
Battery Replacement/Alternative : Fuel Cell replacements for
batteries would offer much longer operating life in a packaged of
lighter or equal weight.
Military Applications : Fuel Cell technology in the military can
help save lives because it reduces telltale heat and noise in
Economic Problems :
Manufacturing cost of fuel-cell power plants is very high.
The most important components of all p.e.m.f.c. and d.m.f.c.’s is
very expensive, about 700 $/m2.
Total cost of a 5-kW p.e.m.f.c power plant is be about 1200 $/kW.
In comparison cost of an analogous I.C. engine is 500-1500 $/kW.
The Problem Of Lifetime :
Satisfactory lifetime for smooth operation.
3 years lifetime for small plants in portable devices.
5 years for electric vehicles.
10 years for large stationary multi-megawatt power plants.
Samples of single p.e.m.f.c and stacks have been successfully
operated for several thousands of hours.
But not enough data available for general use of these type of fuel
RENEWABLE ENERGYACT : FOR INDIA'S FUTURE NEEDS
Solar water heating to be made mandatory throughout the urban
areas of the country by 2012, in a phased manner.
Widespread application of co-generation concepts (heat and
power) for lighting, heating and cooling
Fuel Cells: From Fundamentals to Applications, S. Srinivasan,
Springer, New York, 2006
Fuel Cell History Part 1, G. Wand, “Fuel Cell Today” June 16,
Handbook of Fuel Cells: Fundamentals, Technology, Applications
(four volumes), W. Vielstich, A. Lamm, and H. Gasteiger (editors),
Wiley, Chichester, UK, 2003
"Confusion and Controversy: Nineteenth-Century Theories of the
Voltaic Pile," pp. 133-157 in F. Bevilacqua and L. Fregonese,
Nuova Voltiana: Studies on Volta and his Times, vol. 1 (2000)