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Nonrenewable EnergyChapter 17
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Section 17.1
Energy Resources and Fossil Fuels
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Fossil Fuels
Fossil fuels are the remains of ancient plants and animals that changed into coal, oil, natural gas and methane hydrates (look like ice)
Two problems with fossil fuels: 1. the supply is limited and 2. obtaining and using them causes environmental problems.
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Fuels for different uses
Cooking Transportation Manufacturing Heating and cooling Generating
electricity The fuel we use for
these purposes depends on energy content, cost, availability, safety, and by-products.
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Electricity-Power on Demand How is electricity
generated? An electric generator
is a machine that converts mechanical energy (turbine) into electrical energy.
A turbine is a wheel that changes the force of a moving gas or liquid into energy.
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Combustion Chamber of a Coal-Burning Power Plant
Inside the combustion chamber of a coal-fired power plant burning fossil fuels release energy in the form of heat
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Energy Use
Every product requires energy to produce.
The price of the product reflects the cost of the fuel.
Example: buying a plane ticket includes the cost of the fuel.
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Energy Use in the United States We use more
energy per person than any other country in the world except Canada and the United Arab Emirates.
Most of the energy consumed in the United States is used for industrial purposes.
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How Fossil Fuel Deposits Form
COAL FORMATION
Coal forms from the remains of plants that lived in swamps millions of years ago.
Layers of sediment compressed the plant remains; heat and pressure within the Earth’s crust caused coal to form.
OIL AND NATURAL GAS FORMATION
These form from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago.
These remains were buried in sediments, heated until they became energy-rich carbon based molecules.
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COAL
Most abundant fossil fuel in world
Asia and North America very rich in coal.
Inexpensive Needs little
refining
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Coal Mining and the Environment
Underground mining has minimal effects on environment.
Surface mining does more damage
Move entire mountains and toxic chemical can leach into streams.
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Air Pollution
Higher-grade coals produce less pollution than lower-grade coals.
Burning any coal releases sulfur which leads to air pollution and acid precipitation.
Serious problems in China.
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Petroleum
Oil that is pumped out of ground is called crude oil, or petroleum
Anything made from petroleum is called a petroleum product.
Examples: fuels, chemicals, plastics
Petroleum is 45% of the world’s commercial energy use.
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Oil refinery
An oil refinery converts petroleum into fuel.
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Locating Oil Deposits
Most oil reserves are in Middle East.
Geologist gather data
Exploration wells are drilled
If oil can be extracted at profitable rate, oil is pumped and flows to surface.
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Natural Gas
20% of the world’s nonrenewable energy comes from natural gas (methane)
Burning methane produces fewer pollutants because it burns cleaner.
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Environmental Effects of Using Oil
Burning oil releases pollutants.
Driving cars leads to smog and health problems.
Released carbon dioxide leads to climate change.
Oil spills pollute our waters.
Remember more oil pollutes our water from daily activities.
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Fossil Fuels and the Future Fossil fuels supply
about 90% of the energy used in developed countries.
By 2050, the world energy demands may double (increased population and industry)
Cost of fossil fuels will increase
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Fossil Fuels and the FuturePREDICTING OIL PRODUCTION
Oil reserves are oil deposits that can be extracted profitably
Some oil deposits have not yet been discovered
We must also take into account changing technology
The law of supply and demand
FUTURE OIL RESERVES
Some are located under the ocean, but extracting this oil is much more expensive.
Technology needs to improve and oil extracted from the ocean will cost more than oil extracted from land.
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Time for a reading quiz
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Section 17.2
Nuclear Energy
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Nuclear Energy
In 1950s and 1960s seen as power for the future
Clean and plentiful In 1970s and 1980s, 120 nuclear
power plants were cancelled Why?
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Fission: Splitting Atoms
Nuclear energy is the energy contained in the nuclei of atoms.
Atoms of uranium are used as the fuel in nuclear power plants
Nuclear fission is the splitting of the atomic nuclei.
Releases a tremendous amount of energy.
New nuclei and neutrons result from this splitting.
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How Nuclear Energy Works A nuclear reactor
is surrounded by a thick pressure vessel that is filled with a cooling fluid.
This vessel contains the fission products in case of any accident.
Thick concrete walls surround the reactor
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How Nuclear Energy Works Metal fuel rods
containing solid uranium are bombarded with neutrons.
Chain reaction releases energy and more neutrons.
Rate of reaction is controlled in reactor.
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How Nuclear Energy Works
Heat released during reaction generates electricity.
The energy heats a closed loop of water that heats another body of water.
The water boils, produces steam, and the steam drives a turbine, creating electricity.
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Advantages of Nuclear Energy Very concentrated Does NOT produce
greenhouse gases. Release less
radioactivity than coal-burning power plants.
France generates 3/4ths of its electricity from nuclear power and produces way less air pollution than in U.S.
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Why Aren’t We Using More Nuclear Energy????
Building and maintaining safe reactors is very expensive.
Cost more than $3,000 per kilowatt of electrical capacity.
Wind (less than $1,000/kilowatt)
Natural gas (less than $600/kilowatt)
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Storing Waste
Very difficult to find safe place to store nuclear waste.
Fission products remain radioactive for thousands of years.
Storage sites must be located in areas that are extremely geologically stable.
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Safety Concerns
Fission process can get out of control.
Chernobyl (worst nuclear accident in the world 1986)
Three Mile Island (worst nuclear accident in U.S. 1979)
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Safety Concerns
CHERNOBYL
Ukraine (1986) All safety devices had
been shut off to conduct unauthorized test.
Caused explosion that destroyed reactor.
No containment building. Very old design. Northern Europe and
Ukraine are still contaminated
THREE MILE ISLAND
Pennsylvania (1979) Human error again Blocked valves and
broken pumps Only small amount of
radioactive gas escaped.
More than 300 safety improvements are required for new nuclear power plants.
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The Future of Nuclear Power Nuclear fusion: the
combining of atomic atoms.
A safer energy source due to less radioactive byproducts.
Can release tremendous amounts of energy.
Why don’t we do it????
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Technical Difficulties of Nuclear Fusion
Atomic nuclei must be heated to extremely high temperatures: 100 million degrees C.
Nuclei must be maintained at very high concentrations and confined.
Achieving all three of these simultaneously is extremely difficult.
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Time for a reading quiz