Download ENERGY SOURCES AND GLOBAL WARMING: How Hydrogen …

Global Warming
Project lead the way Ohio
Hocking College
Fuel Cell Training Seminar
July 23 – 27, 2007
Atmospheric Energy Factors
 Earth is in a steady state, the energy stored in the
atmosphere and ocean does not change rapidly over time.
 Energy equal to the absorbed solar radiation must be
radiated back to space.
 Earth radiates energy into space in the infrared
wavelengths with an intensity that increases with
increasing temperature.
 Therefore, one can think of the Earth's temperature as
being determined by the infrared flux needed to balance
the absorbed solar flux.
Layers in the atmosphere
 Troposphere: from 0 – 11
miles high. Contains most
of the air. A thin layer
where our weather occurs.
Ozone here is a pollutant.
NASA shuttle photo of a
sunset over South America
 Stratosphere: from 11 – 30
miles high.
Not as dense as the
troposphere, and contains
much more ozone and less
water vapor.
Greenhouse Effect
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The radiation from the sun is a
different wavelength from the
radiation that is emitted from the
earth’s surface. It easily passes
through the earth’s atmosphere
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The radiation emitted from the
surface is a different wavelength
and ‘Greenhouse gases’ absorb
some it and thus, reducing the
flow of the sun’s heat back into
space.
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Diagram from
www.eecs.umich.edu/mathscience/funexperime
nts/agesubject/lessons/images/diagrampage.ht
ml
Global Warming Definitions
 The amplified warming of the earth’s troposphere as a
result of increases in the concentrations of one or more
greenhouse gases.
 Global warming is the gradual increase in global
temperatures caused by the emission of gases that trap
the sun's heat in the Earth's atmosphere.
 An overall increase in world temperatures which may be
caused by additional heat being trapped by greenhouse
gases.
Greenhouse Gases
 Greenhouse gases (GHG) are gaseous components of
the atmosphere that contribute to the greenhouse effect.
 The major natural greenhouse gases are water vapor,
which causes about 36-70% of the greenhouse effect on
Earth carbon dioxide, which causes between 9-26%;
methane which causes 4 to 9% and ozone, which
causes between 3-7%
 Minor greenhouse gases include, but are not limited to:
methane, nitrous oxide, sulfur hexafluoride, and
chlorofluorocarbons
 Nitrogen and oxygen are not greenhouse gases,
because they do not absorb infrared radiation
Evidence for global warming from Intergovernmental Panel
on Climate Change (2001 report):
The 20th century was the hottest century in the past
1,000 years.
The average global temperature near the earth’s surface
has risen 0.6 degrees C, mostly since 1980.The 16
warmest years on record have occurred since 1980,and the
10 warmest years since 1990.
During the last century the world’s average sea level rose
4-8 inches because of runoff of water from melting
land-based ice, and also because ocean water expands
when its temperature increases.
Global emissions of CO2 now amount to about 24 billion
tons per year, released from fossil fuel combustion
Since 1979 the size of the summer polar ice cap has
shrunk more than 20%. Its thickness has decreased
more than 40%.
Determining CO2 Levels
 Glaciers provide important information about the
composition of the atmosphere through time.
 Gas bubbles (little pieces of ancient atmosphere) are
trapped in glaciers.
 Bubbles can be analyzed for percentages of gases.
 Scientists have found that changes in tropospheric carbon
dioxide correlate well with estimated variations in the
average global temperature.
CO2 Levels from Ice Cores
 After being steady at 280 ppm for 600 years
carbon dioxide levels in the atmosphere have
increased to 340 ppm in the last 250 years.
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Data source: elmhcx9.elmhurst.edu/.../issues/issue197.html
Consequences of Global Warming
 More frequent heat waves, droughts, fires,
costal flooding and storms.
 Some infectious diseases, such as malaria,
will spread to new regions
 High concentrations of ground-level ozone
will exacerbate heart and respiratory
ailments
 By 2080 rising sea levels will flood the
homes and property of millions of people
Response to Global Warming
 Adaptation - Living organisms will learning
how to survive and prosper in a warmer
world.
 Mitigation – Limit the extent of future
warming by reducing the net release of
greenhouse gases to the atmosphere.
– Above responses from Aug 2007 article in
Scientific American
Kyoto Protocol
– The Kyoto Protocol to the United Nations Framework
Convention on Climate Change is an international treaty on
climate change.
– Objective - the assigning mandatory emission limitations
for the reduction of greenhouse gas emissions to the
signatory nations
– Countries which ratify this protocol commit to reduce
their emissions of carbon dioxide and five other
greenhouse gases, or engage in emissions trading if they
maintain or of these gases.
Hydrocarbon Fuels
 Throughout the history of humankind, many different fuels
have been burned to provide energy:
– Wood (used for more than a million years)
– Peat
– Coal (a combustible organic rock composed
primarily of carbon, hydrogen, and oxygen. )
– Oil
– Natural gas
 All of these fuels
contain hydrogen and
carbon. During
combustion, the
carbon and hydrogen
atoms react with
atmospheric oxygen to
produce CO2 and H2O.
(You can not see the
CO2)
Burning Hydrocarbons
 If perfect combustion is obtained the products of
burning a hydrocarbon are CO2 + H2O
Gasoline + Oxygen

2C8H18 + 25O2 
 Methane + Oxygen 
2CH4 + 4O2 
CO2 + H2O
16CO2 + 18H2O
CO2 + H2O
2CO2 + 4H2O
Problem with Coal
CO2 From Vehicles
 The US used 9.15
million barrels of
gasoline per day in
2005
 The US vehicle fleet
adds 1.3 billion tons of
CO2 into the air every
year
Alternative Energy - Politics
 January’s State of the Union Address, President
Bush proposed a “Twenty in Ten” plan to reduce
gasoline usage in the US
 The goal to reduce gasoline usage by 20% in the
next 10 years
 There will be mandatory standards to raise
production of renewable fuels to 35 billion gallons
per year by 2017
Renewable Fuels
 Renewable Fuels are derived from
resources that are regenerative or cannot be
practically depleted.
– Biodiesel
– Ethanol
– Wind Power / Solar Power
– Water Power
– Geothermal Power
Decarburization:
A term scientists use to refer to the changing ratio of carbon to hydrogen
atoms with each succeeding energy source.
 Fuel wood: 10 carbon atoms to 1 hydrogen atom
 Coal: 1 or 2 carbon atoms to 1 hydrogen atom
 Oil: 1 carbon atom to every 2 hydrogen atoms
 Natural gas: One carbon atom to 4 hydrogen atoms
 So…..
 Each successive energy source, when burnt, emits less CO2 than its
predecessor. Pure hydrogen fuel would be best of all.
Alternative Energy Sources
(that do not emit carbon dioxide)
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Solar Power
Hydropower
Geothermal Power
Wind Power
Hydrogen
Nuclear U235
RENEWABLE ENERGY SOURCES INCLUDE BIOMASS,
SOLAR, HYDROPOWER, GEOTHERMAL, WIND POWER
AND HYDROGEN.
Although biomass is a
renewable fuel, its carbon-tohydrogen ratio is not
favorable. Burning wood,
straw, animal feces, etc.
releases a lot of CO2 into the
atmosphere.
SOLAR POWER
Photovoltaic cells directly convert solar energy into
electrical energy. The typical photovoltaic cell is a
transparent wafer that contains a semiconductor.
Sunlight energizes and causes the electrons in the
semiconductor to flow, creating an electrical current.
Solar panels come in many sizes and shapes.
The semiconductor material can be made into
paper-thin sheets that can be incorporated into
traditional looking roofing materials or glass walls.
In some areas, solar energy is a
very good source of power.
This is a large facility in
California.
The main drawback is that the sun must be shining 60%
of the time. So these systems best work in regions with
little cloud cover.
HYDROPOWER
 Downside:
 Often need to construct
 dams. This changes the
flow pattern and ecology of
rivers, and can block the
amount of water farmers
get. Could ultimately lead
to ‘water wars’.
 Some of the water is
allowed to flow through
huge pipes
 at controlled rates,
spinning turbines.
Hydropower
Water flowing from high elevations to lower elevations in
rivers and streams can be controlled by dams and
reservoirs.
With hydropower, flowing water turns the
turbines, which generate electricity.
Ocean currents can also turn turbines.
Because of increasing concern about the harmful
environmental and social effect of large dams, there
has been increasing pressure on the World Bank
and other developmental agencies to stop funding new
large-scale hydropower projects.
GEOTHERMAL ENERGY
Geothermal plants harness heat from the earth’s mantle.
In some places there are steam and hot water pockets
trapped near the surface. This stored energy can be use to
heat buildings and it can be converted into electricity.
In many places the earth’s crust is a constant 55 degrees
Fahrenheit. Geothermal exchange devices can tap into the
difference between the underground and surface
temperatures, using a system of pipes and ducts to heat
or cool a building.
Wind power operates turbines that
generate electricity
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Since 1995, the use of wind
turbines to produce electricity
has increased almost sevenfold.

It has been the world’s fastestgrowing source of energy Europe is
leading the way into the ‘age of
wind energy’.

The DOE calls the Great Plains
states of N. Dakota, S. Dakota,
Nebraska, Kansas, Oklahoma and
Texas the “Saudi Arabia of wind”.

By some calculations they have
enough wind resources meet all the
nation’s electricity needs.
Some people find the wind turbines ‘very ugly’.
They are sometimes a hazard to migrating birds
and can be noisy.
All these forms of clean, renewable energy
(solar, water, geothermal, wind) can produce
electricity.
But it is difficult to store electricity.
Electricity, by its very nature, FLOWS.
Hydrogen can be stored and produce
electricity using fuel cells.
Storage Problem and Electricity
All these forms of clean, renewable energy
(solar, water, geothermal, wind) can produce
electricity.
But it is difficult to store electricity.
Electricity, by its very nature, FLOWS.
Hydrogen can be stored and produce electricity
using fuel cells.
Hydrogen
 Hydrogen gas may be the best fuel to replace oil
during the last half of this century.
 Advantages:
–
–
–
–
–
Plentiful and can be produced from water
No CO2 emissions if produced from water
Easier to store than electricity
Safer than gasoline or natural gas
High efficiency (45 – 65%) in fuel cells.
Burning Hydrogen
 If hydrogen is burned as a fuel the product
of the reaction is simply water vapor.
2H2 + O2
2H2O
Obtaining Hydrogen
 Although the element H is abundant, it is not found
pure in nature.
 The most common method of obtaining hydrogen
is from steam reforming of natural gas.
– This process also produces CO2
 Hydrogen can also be produced from the
electrolysis of water. Electricity is used to split the
water molecule into H2 and O2
– This process does not produces CO2
Another hydrogen-production process being developed
is the reforming of biomass and wastes via ‘pyrolysis’ or
gasification of biomass such as agricultural residues (like
peanut shells and banana skins), consumer wastes like
grease, or biomass grown specifically for energy uses.
SUMMARY
 CO2 levels are increasing and contributing to Global Warming
 Alternative forms of energy (esp. solar and wind) to generate electricity
are becoming more economically attractive
 Hydrogen gas can be used to produce electricity in a fuel cell and solve
the storage problem with electricity
 Adaptation and Mitigation are two primary responses to Global
Warming
 The US is promoting alternative energy - “Twenty in Ten” which will
require using alternative forms of energy for gasoline
RESOURCES
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Rocky Mountain Institute www.rmi.org
http://www.greenenergyohio.org
http://www.rmi.org/sitepages/pid71.php#20H2myths
http://www.nrel.gov/hydrogen/proj_production_delivery.html
http://en.wikipedia.org/wiki/Greenhouse_effect#Basic_mechanism
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The Hype About Hydrogen: Fact and Fiction in the Race to Save the Climate by
Joseph J. Romm. 2004.
The Hydrogen Economy: The Creation of the Worldwide Energy Web and the
Redistribution of Power on Earth by Jeremy Rifkin. 2003.
“Renewable Energy’s Achilles’ Heel” by Lisa Parker, Geotimes, February 2003.
“The Pyhsical Science Behind Climate Change” W. Collins, R. Colman, J.
Haywood, M. Manning, and P. Mote, Scientific American, Aug 2007, pp 64 to 73.
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Resources
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“FUELS AND GLOBAL WARMING: How Hydrogen Can Work with Other
Alternative Energy Sources” – Power Point Presentation by By Linda
Spurlock of Stark State College of Technology July, 2005
 Intergovernmental Panel on Climate Change (2001 report):