1 Conventional “Nonrenewable” Energy
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Energy SourcesEnergy Sources• 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.
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
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Energy Units and UseEnergy Units and Use
• 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
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
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• Units of power:Units of power:
1 watt (W) = 3.412 Btu / hour1 watt (W) = 3.412 Btu / hour
1 horsepower (hp) = 746 W1 horsepower (hp) = 746 W
• Watt-hour - Another unit of energy used only to Watt-hour - Another unit of energy used only to describe electrical energy. Usually we use describe electrical energy. Usually we use kilowatt-hour (kW-h) since it is larger.kilowatt-hour (kW-h) since it is larger.
Energy Units and UseEnergy Units and Use
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
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Evaluating Energy ResourcesEvaluating Energy Resources
• U.S. has 4.6% of world population; uses 24% of the world’s energy;
84% from nonrenewable fossil fuels (oil, coal, & natural gas);
7% from nuclear power;
9% from renewable sources (hydropower, geothermal, solar, biomass).
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Changes in U.S. Energy UseChanges in U.S. Energy Use
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
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Energy resources removed from the earth’s crust include: oil, natural gas, coal, and uranium
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Fossil FuelsFossil Fuels
• 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
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
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Problems with Fossil FuelsProblems with Fossil Fuels
• Fossil fuels are nonrenewable resources• Impurities in fossil fuels are a major source of
pollution• Burning fossil fuels produce large amounts of
CO2
www.lander.edu/rlayland/Chem%20103/chap_12.ppt
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COAL
• 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
• 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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Pros and Cons of Coal
• 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
into the atmosphere
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Cons of Coal Cont.
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
• 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
• 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
• 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)
• 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
• 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
• 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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OilOil
• 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 OilSources 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.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
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Oil in U.S.Oil in U.S.•2.3% of world reserves
•uses nearly 30% of world reserves;
•65% for transportation;
•increasing dependence on imports. www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
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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.
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
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Oil Drilling
• 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 FuelNatural Gas - Fossil Fuel
• Mixture •50–90% Methane (CH4)
•Ethane (C2H6)
•Propane (C3H8)
•Butane (C4H10)
•Hydrogen sulfide (H2S)www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
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Sources of Natural GasSources 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).
www.bio.miami.edu/beck/esc101/Chapter14&15.ppt
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Natural GasNatural Gas
• 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
• Objectives: SWBAT: Discuss the uses and consequences of using
nuclear energy.
• Warmup: Watch 300 years in 300 seconds and what the
future holds.
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Nuclear Energy
• 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?
• 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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Parts of a Nuclear Reactor
• 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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Radioactive Waste Disposal
• 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 IslandThree 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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ChernobylChernobyl• 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
• 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 EnergyUse 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.Nuclear Power Plants in U.S.
cstl-cst.semo.edu/bornstein/BS105/ Energy%20Use%20-%203.ppt
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Objectives and Warmup: 3/29/11
• Objectives: Discuss the environmental and economic
affects of oil spills to ecosystems.
• Warmup: What makes nuclear a desirable energy option?
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Free Writing
• 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.