CEan Arjun_rp

1. GLOBAL WARMING
~HOW FUEL CELLS CAN HELP SOLVE THE PROBLEM~
ABSTRACT
Energy has been the life-blood for continuing progress of human civilization.
Since the beginning of industrial revolution around two hundred years ago, the
global energy consumption has increased dramatically to accelerate our living
standard, particularly in the industrialized nations of the world. Today, the major
portion of world’s electrical energy is generated by fossil fuel and nuclear power
plants.
Besides, burning of fossil fuels, it creates environmental pollution that causes
global warming. Global warming causes sea level rise due to melting of glaciers
and polar ice caps that inundates low-lying areas of the world. Besides, it creates
adverse effect on world climate. The nuclear energy is free from environmental
pollution, but it has safety and serious waste disposal problems.
Increasing emphasis on renewable energy sources, to some extent, will solve the
above problems. Fuel cell is now destined to play a key role in the global energy
conservation scenario.
The presentation will start with broad introduction about global warming, its
causes and consequences, environmental pollution problems by fossil fuels. The
important role of fuel cells as an alternate source of energy will be emphasized.
The role of fuel cells in transportation systems and portable electronic devices will
be discussed.

2. INTRODUCTION
Global warming is the increase in the average temperature of the Earth's near-
surface air and the oceans. The Intergovernmental Panel on Climate Change
(IPCC) concludes that anthropogenic greenhouse gases are responsible for most of
the observed temperature increase since the middle of the twentieth century, and
that natural phenomena such as solar variation and volcanoes probably had a small
warming effect from pre-industrial times to 1950 and a small cooling effect
afterward.
Global mean surface temperature anomaly relative to 1961–1990
CAUSES
GREEN HOUSE GASES
The excessive emission of green house gases are the major cause of global
warming. The green house gases like carbon dioxide, methane, and nitrous oxide
are playing hazards in the present times. These green house gases trap heat in
earth’s atmosphere and thus result in increasing the temperature of earth.
The major source of carbon dioxide is the power plants. These power plants emit
large amounts of carbon dioxide produced from burning of fossil fuels for the
purpose of electricity generation. Coal is the major fuel that is burnt in these
power plants. The coal gives out eighty percent more carbon per unit of energy as
compared to natural gas. Another major source of carbon dioxide in the
atmosphere is the emission from automobiles. About twenty percent of carbon

3. dioxide emitted in the atmosphere comes from burning of gasoline in the engines
of the vehicles.
The second major greenhouse gas after carbon dioxide is Methane. Methane is
more than 20 times as effectual as CO2 at entrapping heat in the atmosphere.
Methane is obtained from resources such as rice paddy fields. When these fields
are flooded, anaerobic situation build up and the organic matter in the soil decays,
releasing methane to the atmosphere.
Nitrous oxide, which is a colorless gas with a sweet odour, is another green house
gas. The main sources of nitrous oxide include nylon and nitric acid production,
the use of fertilizers in agriculture and the burning of organic matter.
DEFORESTATION
Another major cause of global warming is deforestation. Trees collect the CO2
that we breathe out and they give back oxygen that we breathe in. Thus, cutting of
trees is leading to greater concentration of carbon dioxide in the atmosphere.
Greater urbanization, requirement of land for factories and buildings, requirement
of timber are all reasons that are leading to deforestation.
CONSEQUENCES
An increase in global temperatures may in turn cause broader changes in the
environment. Changes in the amount and pattern of precipitation may result in
flooding and drought. There may also be extreme weather events. These changes
are not likely to be reversible on timescales shorter than a thousand years. Other
effects may include changes in agricultural yields, addition of new trade routes,
reduced summer stream flows, species extinctions, and increases in the range of
disease vectors.
A 2001 report by the IPCC suggests that glacier retreat, ice shelf disruption, sea
level rise, changes in rainfall patterns, are attributable in part to global warming.
Other expected effects include water scarcity in some regions, an expanse of the
subtropical desert regions, changes in mountain snow pack, and adverse health
effects from warmer temperatures.

4. FOSSIL FUEL AND IT'S IMPACT ON THE ENVIRONMENT
Fossil fuel can be defined as "incompletely oxidized and decayed animal and
vegetable materials, specifically coal, peat, lignite, petroleum and natural gas". We
retrieve these fossil fuels from the ground and under the sea and have them
converted into electricity. Approximately 90% of the world's electricity demand is
generated from the use of fossil fuels.
Combustion of these fossil fuels is considered to be the largest contributing factor
to the release of greenhouse gases into the atmosphere. The harmful outcomes of
converting fossil fuels to energy are air pollution, water pollution and
accumulation of solid waste.
Air pollution is another problem arising from the use of fossil fuels, and can result
in the formation of smog. Other than causing human illness, smog can also affect
the sustainability of crops.
When coal is burned, it releases nitrous oxide. Unfortunately this is kept in the
atmosphere for very long time. The harmful impact of this chemical could take up
to a couple of hundred years to make itself known. Nearly 50% of the nitrogen
oxide in the atmosphere and 70% of sulfur dioxide are direct result of emissions
released when coal is burned.
Converting fossil fuels may also result in the accumulation of solid waste. This
type of accumulation has a devastating impact on the environment. This type of
waste also increases the risk of toxic runoff which can poison surface and
groundwater sources for many miles. Toxic runoff also endangers surrounding
vegetation, wildlife, and marine life.
We have become a very energy greedy generation and our demands for electricity
are very high. As far as reducing these harmful effects, we must first reduce our
demand and also find an alternate source of energy like fuel cells, tapping non
conventional energy resources that least harms the environment with a very
effectual usage.

5. FUEL CELLS
A fuel cell is an electrochemical conversion device. It converts energy of fuels
directly into electricity without combustion. It produces electricity from fuel (on
the anode side) and an oxidant (on the cathode side), which react in the presence
of an electrolyte. The reactants flow into the cell, and the reaction products flow
out of it, while the electrolyte remains within it. Many combinations of fuel and
oxidant are possible. A hydrogen cell uses hydrogen as fuel and oxygen (usually
from air) as oxidant. Other fuels include hydrocarbons and alcohols, propane-
oxygen fuel cells.
The general reaction is
Fuel + Oxygen  Oxidation product + Energy
HISTORY OF FUEL CELLS
The principle of the fuel cell was discovered by German scientist Christian
Friedrich Schönbein in 1838. Based on this work, the first fuel cell was
demonstrated by Welsh scientist Sir William Robert Grove in the February 1839.
The fuel cell he made used similar materials to today's phosphoric-acid fuel cell.
In 1955, W. Thomas Grubb, a chemist working for the General Electric Company
(GE), further modified the original fuel cell design by using a sulphonated
polystyrene ion-exchange membrane as the electrolyte.
Sketch of William Grove's 1839 fuel cell

6. United Technologies Corporation's UTC Power subsidiary was the first company
to manufacture and commercialize a large, stationary fuel cell system for use as a
co-generation power plant in hospitals, universities and large office buildings.
WORKING OF FUEL CELL (H2 – O2 FUEL CELL)
The hydrogen–oxygen fuel cell consists of two porous electrodes anode and
cathode. Hydrogen (the fuel) is bubbled through the anode compartment, where it
is oxidized. The oxygen (oxidizer) is bubbled through the cathode compartment,
where it is reduced.
AT CATHODE:
The electrons produced at the anode pass through the external wire to the cathode,
where it is absorbed by oxygen and water to produce hydroxide ions.
O2 + 2H2O + 4e-  4OH-
AT ANODE:
Hydrogen molecules are oxidized at the anode with the liberation of electrons,
which then combine with hydroxide ions to form water.
2H2 + 4OH-  4H2O + 4e-
OVERALL CELL REACTION:
2H2 + 2O2  2H2O
ADVANTAGES OF FUEL CELLS

7. 1. Reduced carbon footprint
When fuelled by pure hydrogen the only by-product is water. The inherent
higher efficiency of a well integrated fuel cell installation can significantly
reduce your carbon footprint.
2. Highly efficient
Electrochemical conversion of the fuel is more efficient than combustion and it
produces more electricity per kilowatt of input fuel.
3. Virtually silent and vibration free
The electrochemical process used by fuel cells means there are no moving
parts to generate noise or vibration.
4. Highly reliable
The lack of moving parts means fuel cells can be an incredibly reliable source
of energy.
5. High quality power
Fuel cells provide a virtually perfect sine wave for sensitive electronic
equipment.
6. Continuous source of energy
The fuel is continuously supplied to produce power.
7. Pollution free working
There are no objectionable by–products and therefore, they do not cause
pollution problems.
FUEL CELLS IN REDUCING GLOBAL WARMING

8. In traditional methods of generating electricity, the fuel and air are burned,
generating a high-temperature gas. In the case of a coal-burning power plant, heat
is transferred from this hot gas to high pressure liquid water that is boiled. In the
case of, diesel engine, the hot gas itself is at high pressure. The high-pressure hot
gas is expanded in a mechanical device (e.g. turbine) and ultimately turns on an
electrical generator.
In a fuel cell, the same basic chemical reactions occur, but generate electricity
directly as an electrochemical device and therefore, never go through the step of
being a high-temperature gas through normal burning. This direct conversion of
chemical energy to electrical energy is more efficient and generates much less
pollutants than do traditional methods that rely on combustion. The direct
conversion of fuel and air to electricity is much more efficient than internal
combustion engines and other methods of generating electricity. Therefore, fuel
cells can generate more electricity from the same amount of fuel.
Furthermore, by skipping the combustion process that occurs in traditional power-
generating methods, the generation of pollutants during the combustion process is
avoided and thereby global warming is reduced.
FUEL CELL APPLICATIONS
RACE VEHICLES
Fuel cell powered race vehicles, designed and built by university students from
around the world, competed in the world's first hydrogen race series called the
2008 Formula Zero Championship, in Rotterdam, the Netherlands.
Element One fuel cell vehicle

9. HYDROGEN FUEL CELL TRANSPORTATION
The GM 1966 Electrovan was the automotive industry's first attempt at an
automobile powered by a hydrogen fuel cell. The Electrovan, which weighed more
than twice as much as a normal van, could travel up to 70mph for 30 seconds.
The 2001 Chrysler Natrium used its own on-board hydrogen processor. It
produces hydrogen for the fuel cell by reacting sodium borohydride fuel with
Borax, both of which Chrysler claimed were naturally occurring in great quantity
in the United States. The hydrogen produces electric power in the fuel cell for
near-silent operation and a range of 300 miles without impinging on passenger
space.
Toyota fuel cell vehicle
In 2005 the British firm Intelligent Energy produced the first ever working
motorcycle which run by fuel cell, called the ENV (Emission Neutral Vehicle).
The motorcycle holds enough fuel to run for four hours, and to travel 100 miles in
an urban area, at a top speed of 50 miles per hour..
A hydrogen fuel cell public bus in Perth, Australia

10. .AIRCRAFT INDUSTRY
Boeing researchers and industry partners throughout Europe conducted
experimental flight tests in 2007 of a manned airplane powered only by a fuel cell
and lightweight batteries. The Fuel Cell Demonstrator Airplane research project
was completed recently and thorough systems integration testing is now under
way in preparation for upcoming ground and flight testing. The Boeing
demonstrator uses a Proton Exchange Membrane (PEM) fuel cell/lithium-ion
battery hybrid system to power an electric motor, which is coupled to a
conventional propeller.
FUEL CELLS IN PORTABLE ELECTRONIC DEVICES
LAPTOPS
A new scheme for creating a compact device that efficiently converts methanol
into hydrogen could make it practical to incorporate fuel cells into laptop
computers and other portable electronics. Such a device could allow a laptop to
run for 50 hours and be recharged instantly by swapping in a small fuel pack.
OTHER ELECTRONIC DEVICES
Fuel cell is packaged into portable devices such as cellular phones, digital
cameras, camcorders, and power tools. Portable devices are seen as employing up
to 100 watt hours of energy, with supplemental energy available through refueling
cartridges.
Examples include:
• Cellular Phones (1 - 3 W)
• Camcorders (2 -5 W)
• Cordless Tools (20 - 200 W)
POWER GENERATORS
Small Portable Power Generators refer to units up to 20 pounds in weight, up to 3
- 5 KW power. Examples of applications include power for camping and other
recreational activity or short-term power in an emergency.

11. OTHER APPLICATIONS
• Base load power plants
• Electric and hybrid vehicles.
• Auxiliary power
• Off-grid power supply
• Notebook computers for applications where AC charging may not be
available for weeks at a time.
• Portable charging docks for small electronics (e.g. a belt clip that charges
your cell phone or PDA).
• Smart phones with high power consumption due to large displays and
additional features like GPS might be equipped with micro fuel cells.
• Energy source in space vehicles, submarines and other military
applications.
CONCLUSION
In this paper an efficient way in reducing global warming by the use of fuel cells
has been emphasized. Hence it clearly reveals that fuel cell products are pollution
free. There are researches and studies happening around the world to implement
fuel cells in transportation and portable electronic devices in large scale in a cost
effective manner. So a pollution free earth with less global warming is not far
ahead.
FUTURESCOPE
There has been a concerted effort in some countries to move to less polluting
forms of public transport. In India, Delhi ranks as one of the world’s worst cities
for urban air pollution, banned diesel buses from its streets and plans to use
hydrogen in internal combustion engines, and eventually to install fuel cells.
A survey envisages that one million hydrogen fuelled vehicles will be on Indian
roads by 2020. REVA, the electric car company, manufacturer of India’s first
electric car, has a fuel cell version of the REVA-EV at developmental stage.

12. The REVA fuel cell car
The Department of Science and Technology (DST) has established a Centre for
Fuel Cell Technology (CFCT) located in Chennai with the specific objective of
demonstrating and validating commercial applications of PEM fuel cells in
collaboration with industries.
~ BY ~
ARJUN.R.PALANIAPPAN
CE ID: 9df8296aecafd33e60d8e4470e54e95693d3bb45