Transcript Chapter 19 nonrenewable energy

Conventional “Nonrenewable” Energy
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Energy Sources
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Primary Energy Resources: fossil fuels (oil, gas, and
coal), nuclear energy, falling water, geothermal, and solar
energy.
• Secondary Energy Resources: Sources derived from
primary resources such as electricity, fuels from coal,
(synthetic natural gas and synthetic gasoline), as well as
alcohol fuels.
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Energy Units and Use
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Btu (British thermal unit) - amount of energy
required to raise the temperature of 1 lb of water
by 1 ºF.
cal (calorie) - amount of energy required to raise
the temperature of 1 g of water by 1 ºC.
Commonly, kilocalorie (kcal) is used.
1 Btu = 252 cal = 0.252 kcal
1 Btu = 1055 J (joule) = 1.055 kJ
1 cal = 4.184 J
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Energy Units and Use
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Units of power:
1 watt (W) = 3.412 Btu / hour
1 horsepower (hp) = 746 W
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Watt-hour - Another unit of energy used only to
describe electrical energy. Usually we use
kilowatt-hour (kW-h) since it is larger.
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Evaluating Energy Resources
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U.S. has 4.6% of world population; uses
24% of the world’s energy;

84% from nonrenewable fossil fuels (oil,
coal, & natural gas);
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7% from nuclear power;
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9% from renewable sources (hydropower,
geothermal, solar, biomass).
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Changes in U.S. Energy Use
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Energy resources removed from the
earth’s crust include: oil, natural gas,
coal, and uranium
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Fossil Fuels
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Fossil fuels originated from the decay of living
organisms millions of years ago
The fossil fuels used in energy generation are:
 Natural gas, which is 70 - 80% methane (CH4)
 Petroleum
 Coal
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Problems with Fossil Fuels
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Fossil fuels are nonrenewable resources
Impurities in fossil fuels are a major source of
pollution
Burning fossil fuels produce large amounts of
CO2
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COAL
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Coal-fossilized plant material preserved in
sediments, compacted and condensed over time
to create a solid fossil fuel
 Made up of:
- Carbon
- Water, sulfur, mercury and small amounts of
radioactive materials
 As coal ages, carbon ↑ while water ↓
 Carboniferous period (286 million to 360
million years ago).
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Types of Coal
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Peat
 Partially decayed organic matter in swamps and bogs
Lignite (4000 BTU/lb)
 Soft, brownish-black coal
 Low quality of coal
Subbituminous (8,300 BTU/lb.)
 Black lignite
Bituminous (10,500 Btu / lb.)
 Dense and black
 Most common coal
 “soft coal”
Anthracite (14,000 Btu/lb)
 98% carbon (less common and more expensive)
 “hard coal”
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PEAT
LIGNITE
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BITUMINOUS
ANTHRACITE
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Main Coal Deposits
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Pros and Cons of Coal
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Pros:
 Most abundant fossil fuel
 Major U.S. reserves
 High net energy yield
Cons:
 High environmental impact
- Severe land disturbance in mining
 High carbon dioxide (dirtiest fuel)
 Sulfur is released primarily as sulfur dioxide
 Releases radioactive particles and toxic metals
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into the atmosphere
Cons of Coal Cont.
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Negative impact on miners
- Death
 Between 1870 and 1950, more than
30,000 coal miners died of accidents and
injuries in Pennsylvania alone.
- Black Lung Disease - Inflammation and
fibrosis caused by accumulation of coal dust
in the lungs or airways.
- Several thousands have died of respiratory
diseases.
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Objectives and Warmup: 3/22/11
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Objectives:
 Discuss the uses and consequences of using
coal.
Warmup:
 Why do developed countries get the majority
of their energy from non-renewable sources?
Can this practice continue? For how long?
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Mining
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2 types of mining
 Strip-Mining or Open Pit Mining
- Topsoil and vegetation is removed
- Negative impacts
 Air quality issues regarding dust
 Large amounts of waste material involved
 Habitats destroyed/Soil is dumped back to
where it was
 Toxic runoff
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Mining
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Underground Mining-large shafts dug into the
earth
 Less surface destruction and waste rock
produced
 Extremely Dangerous
- Gas
- Inhaling Particulate Matter
- Tunnel Collapse
- Acid mine drainage
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Acid Mine Drainage (AMD)
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Acid mine drainage-water containing iron and
sulfate that contaminates surface and or
groundwater
 May also contain manganese and aluminum
 AMD comes from oxidation of pyrite, the
crystalline form of iron sulfide
- contaminated water is often reddish-brown
in color, indicating high levels of oxidized
iron
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Restoration
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Surface Mining Control and Reclamation Act
(1977) requires better restoration of strip-mined
lands, especially if land classed as prime
farmland.
 Difficult and expensive.
- Minimum reclamation costs about $1,000 /
acre while complete restoration may cost
$5,000 / acre.
 50% of U.S. coal is strip mined.
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Objectives and Warmup: 3/24/11
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Objectives:
 Discuss the uses and consequences of using
coal, petroleum, and natural gas.
Warmup:
 Was the environment during your mining
simulation ever taken in to account?
 If you could have chosen your land or mining
tools differently what would you have used?
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Oil
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Decomposition of deeply buried organic matter
from plants & animals
 Crude oil: complex liquid mixture of
hydrocarbons, with small amounts of S, O, N
impurities
Trapped within the earth's crust and can be
extracted by drilling a well
How Oil Drilling Works by Craig C. Freudenrich, Ph.D.
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Sources of Oil
•Organization of Petroleum Exporting Countries
(OPEC) -- 13 countries have 67% world
reserves:
• Algeria, Ecuador, Gabon, Indonesia, Iran,
Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi
Arabia, United Arab Emirates, & Venezuela
• Other important producers:
Alaska, Siberia, & Mexico.
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Oil in U.S.
•2.3% of world
reserves
•uses nearly 30%
of world
reserves;
•65% for
transportation;
•increasing
dependence on
imports.
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Low oil prices have stimulated economic growth, they
have discouraged / prevented improvements in energy
efficiency and alternative technologies favoring
renewable resources.
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Oil Drilling
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Causes only moderate damage to earth’s land
- Oil companies extract oil in fragile
environments (Artic tundra/Alaska)
Transported to a refinery where it is heated and
distilled to separate the components
How Oil Drilling Works by Craig C. Freudenrich, Ph.D.
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Natural Gas - Fossil Fuel
• Mixture
•50–90% Methane (CH4)
•Ethane (C2H6)
•Propane (C3H8)
•Butane (C4H10)
•Hydrogen sulfide (H2S)
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Sources of Natural Gas
•Russia & Kazakhstan - almost 40% of
world's supply.
•Iran (15%), Qatar (5%), Saudi Arabia
(4%), Algeria (4%), United States (3%),
Nigeria (3%), Venezuela (3%);
•90–95% of natural gas in U.S. domestic
(~411,000 km = 255,000 miles of
pipeline).
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billion cubic metres
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Natural Gas
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Experts predict increased use of natural gas
during this century
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Natural Gas
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When a natural gas field is tapped, propane and
butane are liquefied and removed as liquefied
petroleum gas (LPG)
The rest of the gas (mostly methane) is dried,
cleaned, and pumped into pressurized pipelines
for distribution
Liquefied natural gas (LNG) can be shipped in
refrigerated tanker ships
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Objectives and Warmup: 3/28/11
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Objectives: SWBAT:
 Discuss the uses and consequences of using
nuclear energy.
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Warmup:
 Watch 300 years in 300 seconds and what the
future holds.
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Nuclear Energy
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Most commonly used fuel is U235 (naturally
occurring radioactive isotope of uranium.)
- Formed in cylindrical pellets (1.5 cm long)
and stacked in hollow metal rods (4 m long).
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How Do Nuclear Reactors Work?
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Nuclear Fission Chain Reactor-neutrons strike
radioactive uranium atoms (U-235) releasing
energy and more neutrons.
 Triggers nuclear chain reaction.
 Heats water that produce high-pressure steam
that turns turbines-generates electricity.
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Nuclear Fission
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Parts of a Nuclear Reactor
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Core-contains 35-50,000 long thin fuel rods packed with
U235
 Each pellet contains the energy equivalent of 1 ton of
coal)
Control rods-absorb neutrons and controls reaction rate
 Raising and lowering the control rods into the reactor
regulates the amount of heat produced
Moderator-reduces velocity of fast moving neutrons
 Water, graphite
Coolant-(water) circulates through the reactor’s core to
remove heat to keep fuel rods from melting
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PWR
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Radioactive Waste Disposal
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Need to dispose of radioactive wastes that are
produced
 High level wastes-used fuel rods, control rods,
water used to cool and control chain reactions
 Medium to low level wastes-mine wastes,
contaminated protective clothes of a power
plant worker
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Three Mile Island
• March 29, 1979, a reactor near Harrisburg, PA lost
coolant water because of mechanical and human
errors and suffered a partial meltdown
• 50,000 people evacuated & another 50,000 fled area
• Unknown amounts of radioactive materials released
• Partial cleanup & damages cost $1.2 billion
• Released radiation increased cancer rates.
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Chernobyl
• April 26, 1986, reactor explosion (Ukraine) with a
severe release of radioactivity
• No containment vessels
• Plume of radioactivity drifted over extensive parts of
western Europe and 336,000 people were resettled
• ~160,000 sq km (62,00 sq mi) contaminated
• > Half million people exposed to dangerous levels of
radioactivity
• Cost of incident > $358 billion
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Japan: Tokyo Electric Power Company's (TEPCO)
Fukushima Daiichi
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3/11/11: 9.0 earthquake caused tsunami that went over
seawalls and flooded generators
 Generators died which stopped the coolant pumps
 Temperature rose above 2200ºF caused vessels to vent
hydrogen caused several explosions
 Pumped sea water mixed with boron into the
containment vessels
Residents living within 20 kilometers of the plant are
told to evacuate the area after first explosions.
Estimated cost of damage from the earthquake and
tsunami to top $300 billion, making it the world's
costliest natural disaster.
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Use of Nuclear Energy
• Some countries (France, Japan) investing increasingly
• France 58 reactors supply 75% energy
• Japan 54 reactors supply 29% of energy
• U.S. 104 reactors supply 20% energy
• 1996 last new reactor opened
• Cost today: ~$10 billion
• 71,862 tons of the waste and no permanent place to
store it all.
• ¾ of waste stored in water-filled cooling pools stored inside
concrete containment barriers
• ¼ waste is encased in "dry casks" constructed of steel and
thick concrete.
• Yucca Mountain in Nevada
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Nuclear Power Plants in U.S.
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Objectives and Warmup: 3/29/11
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Objectives:
 Discuss the environmental and economic
affects of oil spills to ecosystems.
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Warmup:
 What makes nuclear a desirable energy option?
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Free Writing
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The only available energy resources left on our
planet are nonrenewable. Choose one of the
nonrenewable energy resources that you believe
has the least environmental impact on our Earth.
Support your choice with at least two reasons
your resources should be chosen over other
nonrenewable sources.
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