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Nonrenewable EnergyNonrenewable Energy
ENERGYENERGY
Energy is the ability to do work and transfer Energy is the ability to do work and transfer heat.heat. Kinetic energy – energy in motionKinetic energy – energy in motion
• heat, electromagnetic radiationheat, electromagnetic radiation Potential energy – stored for possible usePotential energy – stored for possible use
• batteries, glucose moleculesbatteries, glucose molecules
ENERGY LAWS: TWO RULES WE ENERGY LAWS: TWO RULES WE CANNOT BREAKCANNOT BREAK
The first law of thermodynamics: we cannot The first law of thermodynamics: we cannot create or destroy energy.create or destroy energy. We can change energy from one form to another.We can change energy from one form to another.
The second law of thermodynamics: energy The second law of thermodynamics: energy quality always decreases.quality always decreases. When energy changes from one form to another, When energy changes from one form to another,
it is always degraded to a more dispersed form.it is always degraded to a more dispersed form. Energy efficiency is a measure of how much Energy efficiency is a measure of how much
useful work is accomplished before it changes to useful work is accomplished before it changes to its next form.its next form.
Resources are renewable or Resources are renewable or nonrenewablenonrenewable
Renewable energy = supplies of energy will Renewable energy = supplies of energy will not be depleted by our usenot be depleted by our use Sunlight, geothermal energy, and tidal energySunlight, geothermal energy, and tidal energy
Nonrenewable energy = at our current rates Nonrenewable energy = at our current rates of consumption we will use up Earth’s of consumption we will use up Earth’s accessible store of these sources in a matter accessible store of these sources in a matter of decades to centuriesof decades to centuries Oil, coal, natural gas, nuclear energyOil, coal, natural gas, nuclear energy To replenish the fossil fuels we have depleted so To replenish the fossil fuels we have depleted so
far would take millions of yearsfar would take millions of years
Humans do a lot of activities that require Humans do a lot of activities that require outside energy sources or fuelsoutside energy sources or fuels
What are some big things that we use “fuels” What are some big things that we use “fuels” for?for? TransportationTransportation Manufacture/buildingManufacture/building Heating and cooling Heating and cooling Generating electricity – make sure you know how Generating electricity – make sure you know how
we do thiswe do this OthersOthers
Which of the “Fuels” (from the slide above) Which of the “Fuels” (from the slide above) do we use most for which activities?do we use most for which activities?
Electricity is Moving ElectronsElectricity is Moving Electrons The electrons near the nucleus are held tight The electrons near the nucleus are held tight
to the atom. Sometimes, the ones farthest to the atom. Sometimes, the ones farthest away are not. We can push some of these away are not. We can push some of these electrons out of their energy levels. We can electrons out of their energy levels. We can move them. Moving electrons are called move them. Moving electrons are called electricity.electricity.
Magnets Can Make ElectricityMagnets Can Make Electricity We can use magnets to make electricity. A We can use magnets to make electricity. A magnetic field magnetic field
can pull and push electrons to make them move. can pull and push electrons to make them move. Some metals, like copper, have electrons that are Some metals, like copper, have electrons that are loosely held. They are easily pushed from their shells.loosely held. They are easily pushed from their shells.
Magnetism and electricity are related. Magnets can create Magnetism and electricity are related. Magnets can create electricity and electricity can produce magnetic fields. electricity and electricity can produce magnetic fields. Every time a magnetic field changes, an electric field is Every time a magnetic field changes, an electric field is created. Every time an electric field changes, a magnetic created. Every time an electric field changes, a magnetic field is created. Magnetism and electricity are always field is created. Magnetism and electricity are always linked together; you can’t have one without the other. This linked together; you can’t have one without the other. This is called is called electromagnetism.electromagnetism.
Power Plants Use MagnetsPower Plants Use Magnets Power plants use huge magnets to make, or Power plants use huge magnets to make, or
generate, electricity. In a generate, electricity. In a generator, a big coil of generator, a big coil of copper wire spins inside the magnets. As it copper wire spins inside the magnets. As it spins, the magnetic fields push and pull spins, the magnetic fields push and pull electrons in the wire. electrons in the wire.
The electrons in the copper wire flow into power The electrons in the copper wire flow into power lines. These moving electrons are the electricity that lines. These moving electrons are the electricity that powers our houses.powers our houses.
Power plants use giant wheels, called Power plants use giant wheels, called turbines, to turbines, to spin the coils of wire in the generators. It takes spin the coils of wire in the generators. It takes a lot of energy to spin turbines. Power plants a lot of energy to spin turbines. Power plants use many fuels to get that energy.use many fuels to get that energy.
So anything that can turn a turbine can be So anything that can turn a turbine can be used to generate electricityused to generate electricity
TYPES OF ENERGY RESOURCESTYPES OF ENERGY RESOURCES
Commercial energy use by source for the Commercial energy use by source for the world (left) and the U.S. (right).world (left) and the U.S. (right).
Figure 16-3Figure 16-3
There are three fossil fuels:There are three fossil fuels: coal, oil and natural gas.coal, oil and natural gas.
Fossil fuels are non-renewableFossil fuels are non-renewable Today coal is the predominant fossil fuel used toToday coal is the predominant fossil fuel used togenerate electricity supplying approximately 52% generate electricity supplying approximately 52%
of the market.of the market. Petroleum products supplies very little electricity.Petroleum products supplies very little electricity. Natural gas supplies approximately 16% of our Natural gas supplies approximately 16% of our
electricity.electricity.
Fossil fuels are our dominant Fossil fuels are our dominant source of energysource of energy
Fossil fuels have replaced Fossil fuels have replaced biomass as our dominantbiomass as our dominant
source of energysource of energy The high-energy content of The high-energy content of
fossil fuels makes themfossil fuels makes themefficient to burn, ship, and storeefficient to burn, ship, and store These fuels generate These fuels generate
electricity = a secondary electricity = a secondary form of form of energy that is easier energy that is easier to transfer and apply to a to transfer and apply to a variety of usesvariety of uses
Fossil fuel reserves are unevenlyFossil fuel reserves are unevenlydistributeddistributed
Some regions have substantial reserves, Some regions have substantial reserves, whereas others have very fewwhereas others have very few
How long a nation’s reserves will last How long a nation’s reserves will last depends on:depends on: How much the nation extracts, uses, and exportsHow much the nation extracts, uses, and exports
Nearly 67% of the world’s proven reserves of Nearly 67% of the world’s proven reserves of crude oil lie in the Middle Eastcrude oil lie in the Middle East
The U.S. possesses more coal than any The U.S. possesses more coal than any other countryother country
Developed nations consume lots ofDeveloped nations consume lots ofenergyenergy
People in developed regions consume far People in developed regions consume far more energy than those in developing nationsmore energy than those in developing nations
Industrialized nations divide their energy use Industrialized nations divide their energy use evenly between transportation, industry, and evenly between transportation, industry, and other usesother uses Developing nations use energy for subsistence Developing nations use energy for subsistence
activities (agriculture, food preparation, and home activities (agriculture, food preparation, and home heating)heating)
Developing nations use manual or animal energy Developing nations use manual or animal energy instead of fossil fuelsinstead of fossil fuels
OILOIL Crude oil (petroleum) is a thick liquid Crude oil (petroleum) is a thick liquid
containing hydrocarbons that we extract from containing hydrocarbons that we extract from underground deposits and separate into underground deposits and separate into products such as gasoline, heating oil and products such as gasoline, heating oil and asphalt.asphalt. Only 35-50% can be economically recovered Only 35-50% can be economically recovered
from a deposit.from a deposit. As prices rise, about 10-25% more can be As prices rise, about 10-25% more can be
recovered from expensive secondary extraction recovered from expensive secondary extraction techniques.techniques.• This lowers the net energy yield.This lowers the net energy yield.
The age of oil began in the mid-19The age of oil began in the mid-19thth century century
People have used solid forms of oil (i.e., tar) for thousands People have used solid forms of oil (i.e., tar) for thousands of yearsof years
Modern extraction and use began in the 1850sModern extraction and use began in the 1850s First bottled and sold as a healing aid, but it is First bottled and sold as a healing aid, but it is
carcinogeniccarcinogenic This “rock oil” could be used in lamps and as a lubricantThis “rock oil” could be used in lamps and as a lubricant Edwin Drake drilled the world’s first oil well, in Titusville, Edwin Drake drilled the world’s first oil well, in Titusville,
Pennsylvania, in 1859Pennsylvania, in 1859 Today, the U.S. consumes 25% of the world’s oilToday, the U.S. consumes 25% of the world’s oil
Consumption is still increasingConsumption is still increasing
Heat and pressure underground Heat and pressure underground form petroleumform petroleum
Oil is the world’s most used fuel since the 1960sOil is the world’s most used fuel since the 1960s It’s worldwide use over the past decade has risen 17%It’s worldwide use over the past decade has risen 17% Crude oil (petroleum) = a mixture of hundreds of different Crude oil (petroleum) = a mixture of hundreds of different
types of hydrocarbon moleculestypes of hydrocarbon molecules Formed 1.5 - 3 km (1 - 2 mi) undergroundFormed 1.5 - 3 km (1 - 2 mi) underground Dead organic material was buried in marine sediments Dead organic material was buried in marine sediments
and transformed by time, heat, and pressureand transformed by time, heat, and pressure Refineries separate crude oil into components such as gas, Refineries separate crude oil into components such as gas,
tar, and asphalt based on boiling pointstar, and asphalt based on boiling points
Not all oil can be extractedNot all oil can be extracted
Some oil would be so hard to extract, it is not Some oil would be so hard to extract, it is not worth the costworth the cost As prices rise, economically recoverable As prices rise, economically recoverable
amounts approach technically recoverable amounts approach technically recoverable amountsamounts
Proven recoverable reserve = the amount of Proven recoverable reserve = the amount of oil (or any oil (or any other fossil fuel) that is technically other fossil fuel) that is technically and economically feasible to remove under and economically feasible to remove under current conditionscurrent conditions
We drill to extract oilWe drill to extract oil Exploratory drilling = small, deep holes to Exploratory drilling = small, deep holes to
determine whether extraction should be donedetermine whether extraction should be done Oil is under pressure and often rises to the Oil is under pressure and often rises to the
surfacesurface Primary extraction = the initial drilling and pumping Primary extraction = the initial drilling and pumping
of available oilof available oil Secondary extraction = solvents, water, or steam is Secondary extraction = solvents, water, or steam is
used to remove additional oil; expensiveused to remove additional oil; expensive We lack the technology to remove every bit of oilWe lack the technology to remove every bit of oil As prices rise, it becomes economical to reopen a As prices rise, it becomes economical to reopen a
wellwell
Primary and secondary oil Primary and secondary oil extractionextraction
OILOIL
Eleven OPEC (Organization of Petroleum Eleven OPEC (Organization of Petroleum Exporting Countries) have 78% of the world’s Exporting Countries) have 78% of the world’s proven oil reserves and most of the world’s proven oil reserves and most of the world’s unproven reserves.unproven reserves.
After global production peaks and begins a After global production peaks and begins a slow decline, oil prices will rise and could slow decline, oil prices will rise and could threaten the economies of countries that threaten the economies of countries that have not shifted to new energy alternatives.have not shifted to new energy alternatives.
Extracted oil is refined to create many Extracted oil is refined to create many productsproducts
OILOIL Refining crude oil:Refining crude oil:
Based on boiling Based on boiling points, components points, components are removed at are removed at various layers in a various layers in a giant distillation giant distillation column.column.
The most volatile The most volatile components with components with the lowest boiling the lowest boiling points are removed points are removed at the top.at the top.
Figure 16-5Figure 16-5
Oil production is expected to peak in the near Oil production is expected to peak in the near future as reserves depletefuture as reserves deplete
Amount of untapped oil reserves hard to predictAmount of untapped oil reserves hard to predict Companies and governments do not disclose their Companies and governments do not disclose their
amount of oil supplyamount of oil supply Disagreement among geologistsDisagreement among geologists Oil consumption increases at an unpredictable rate Oil consumption increases at an unpredictable rate
in developing countriesin developing countries Survival after oil depletion depends on research Survival after oil depletion depends on research
of new technologies and energy conservationof new technologies and energy conservation
Peaking oil production will havePeaking oil production will haveconsequencesconsequences
Coming divergence of demand and supply will have Coming divergence of demand and supply will have momentous economic, social, and political consequencesmomentous economic, social, and political consequences Our lives will be profoundly affectedOur lives will be profoundly affected
““The long emergency”: from lacking cheap oil to transport The long emergency”: from lacking cheap oil to transport goods, our economies collapse and become localizedgoods, our economies collapse and become localized Suburbs will become the new slums, a crime-ridden Suburbs will become the new slums, a crime-ridden
landscape littered with the hulls of rusted out carslandscape littered with the hulls of rusted out cars More optimistic observers argue that as supplies dwindle, More optimistic observers argue that as supplies dwindle,
conservation and alternative energy supplies will kick inconservation and alternative energy supplies will kick in We will be saved from major disruptionsWe will be saved from major disruptions
Some people calculate that we have used up Some people calculate that we have used up about 1.1 trillion barrels of oilabout 1.1 trillion barrels of oil
Reserves-to-production ratio (R/P ratio) = the Reserves-to-production ratio (R/P ratio) = the amount of total remaining reserves divided by amount of total remaining reserves divided by the annual rate of production (extraction and the annual rate of production (extraction and processing)processing) At current levels of production (30 billion At current levels of production (30 billion
barrels/year), we have about 40 years of oil leftbarrels/year), we have about 40 years of oil left We will face a crisis not when we run out of oil, We will face a crisis not when we run out of oil,
but when the rate of production begins to declinebut when the rate of production begins to decline
Case Study: U.S. Oil SuppliesCase Study: U.S. Oil Supplies
The U.S. – the world’s largest oil user – has The U.S. – the world’s largest oil user – has only 2.9% of the world’s proven oil reserves.only 2.9% of the world’s proven oil reserves.
U.S oil production peaked in 1974 (halfway U.S oil production peaked in 1974 (halfway production point).production point).
About 60% of U.S oil imports goes through About 60% of U.S oil imports goes through refineries in hurricane-prone regions of the refineries in hurricane-prone regions of the Gulf Coast.Gulf Coast.
Core Case Study: Core Case Study: How Long Will the Oil Party Last? How Long Will the Oil Party Last?
Saudi Arabia could supply the world with oil Saudi Arabia could supply the world with oil for about 10 years.for about 10 years.
The Alaska’s North Slope could meet the The Alaska’s North Slope could meet the world oil demand for 6 months (U.S.: 3 world oil demand for 6 months (U.S.: 3 years).years).
Alaska’s Arctic National Wildlife Refuge Alaska’s Arctic National Wildlife Refuge would meet the world demand for 1-5 would meet the world demand for 1-5 months (U.S.: 7-25 months).months (U.S.: 7-25 months).
Core Case Study: Core Case Study: How Long Will the Oil Party Last? How Long Will the Oil Party Last?
We have three We have three options:options: Look for more oil.Look for more oil. Use or waste less oil.Use or waste less oil. Use something else.Use something else.
Figure 16-1Figure 16-1
The U.S. enacted policies to reduceThe U.S. enacted policies to reduceforeign oilforeign oil
The U.S. government enacted policies to diversify The U.S. government enacted policies to diversify its oil supplyits oil supply It imports oil from several countriesIt imports oil from several countries The U.S. is developing its own reservesThe U.S. is developing its own reserves Proposed drilling in ANWR, despite charges that drilling Proposed drilling in ANWR, despite charges that drilling
won’t help muchwon’t help much Resuming extraction at currently closed sitesResuming extraction at currently closed sites Research into renewable energy sourcesResearch into renewable energy sources The The Strategic Petroleum Reserve stockpiles oil in Strategic Petroleum Reserve stockpiles oil in
caverns under caverns under Louisiana for use when world supplies Louisiana for use when world supplies run outrun out
But this reserve equals just one month’s supplyBut this reserve equals just one month’s supply
OILOIL
Burning oil for Burning oil for transportation transportation accounts for 43% accounts for 43% of global COof global CO22 emissions.emissions.
Figure 16-7Figure 16-7
Heavy Oils from Oil Sand and Oil Heavy Oils from Oil Sand and Oil Shale: Will Sticky Black Gold Save Us?Shale: Will Sticky Black Gold Save Us? Heavy and tarlike oils from oil sand and oil Heavy and tarlike oils from oil sand and oil
shale could supplement conventional oil, but shale could supplement conventional oil, but there are environmental problems.there are environmental problems. High sulfur content.High sulfur content. Extracting and processing produces:Extracting and processing produces:
• Toxic sludgeToxic sludge• Uses and contaminates larges volumes of waterUses and contaminates larges volumes of water• Requires large inputs of natural gas which reduces net Requires large inputs of natural gas which reduces net
energy yield.energy yield.
Oil ShalesOil Shales
Oil shales contain Oil shales contain a solid a solid combustible combustible mixture of mixture of hydrocarbons hydrocarbons called called kerogenkerogen..
Figure 16-9Figure 16-9
Oil shale = sedimentary rock filled with Oil shale = sedimentary rock filled with kerogen kerogen (organic matter) that can be (organic matter) that can be processed to produce liquid petroleumprocessed to produce liquid petroleum Can be burned like coal or baked in hydrogen Can be burned like coal or baked in hydrogen
(called (called pyrolosis) to produce liquid petroleumpyrolosis) to produce liquid petroleum More than 40% is found in the U.S., mostly More than 40% is found in the U.S., mostly
on federally owned land in the weston federally owned land in the west Low prices for crude oil have kept investors Low prices for crude oil have kept investors
awayaway But as oil prices increase, oil shale is gaining But as oil prices increase, oil shale is gaining
interestinterest
Heavy OilsHeavy Oils
It takes about 1.8 It takes about 1.8 metric tons of oil metric tons of oil sand to produce sand to produce one barrel of oil.one barrel of oil.
Figure 16-10Figure 16-10
Oil sands can be mined and processedOil sands can be mined and processed Oil sands (tar sands) = sand Oil sands (tar sands) = sand deposits deposits
with 1 - 20% with 1 - 20% bitumen, bitumen, a thick form of a thick form of petroleum rich in carbon, poor in petroleum rich in carbon, poor in hydrogenhydrogen Degraded and chemically altered crude oil Degraded and chemically altered crude oil
depositsdeposits Removed by strip miningRemoved by strip mining
Requires special extraction and refining Requires special extraction and refining processes to become usefulprocesses to become useful
Primarily found in Venezuela and AlbertaPrimarily found in Venezuela and Alberta
NATURAL GASNATURAL GAS
Natural gas, consisting mostly of methane, is Natural gas, consisting mostly of methane, is often found above reservoirs of crude oil.often found above reservoirs of crude oil. When a natural gas-field is tapped, gasses are When a natural gas-field is tapped, gasses are
liquefied and removed as liquefied petroleum gas liquefied and removed as liquefied petroleum gas (LPG).(LPG).
Coal beds and bubbles of methane trapped Coal beds and bubbles of methane trapped in ice crystals deep under the arctic in ice crystals deep under the arctic permafrost and beneath deep-ocean permafrost and beneath deep-ocean sediments are unconventional sources of sediments are unconventional sources of natural gas.natural gas.
Natural gas is formed in two waysNatural gas is formed in two ways Natural gas = consists of methane (CH4) Natural gas = consists of methane (CH4)
and other and other volatile hydrocarbonsvolatile hydrocarbons 1. Biogenic gas = created at shallow 1. Biogenic gas = created at shallow
depths by depths by bacterial anaerobic decomposition bacterial anaerobic decomposition of organic matterof organic matter ““swamp gas”swamp gas”
2. Thermogenic gas = results from 2. Thermogenic gas = results from compression and compression and heat deep undergroundheat deep underground
Natural gas is often wastedNatural gas is often wasted
Coalbed methane = from coal seams, Coalbed methane = from coal seams, leaks to the leaks to the atmosphere during miningatmosphere during mining
In remote oil-drilling areas, natural gas is In remote oil-drilling areas, natural gas is flared: simply burned offflared: simply burned off In Alaska, gas captured during oil drilling is being In Alaska, gas captured during oil drilling is being
reinjected into the ground for future usereinjected into the ground for future use Landfills produce biogenic natural gasLandfills produce biogenic natural gas
Operators are capturing and selling itOperators are capturing and selling it
NATURAL GASNATURAL GAS
Russia and Iran have almost half of the Russia and Iran have almost half of the world’s reserves of conventional gas, and world’s reserves of conventional gas, and global reserves should last 62-125 years.global reserves should last 62-125 years.
Natural gas is versatile and clean-burning Natural gas is versatile and clean-burning fuel, but it releases the greenhouse gases fuel, but it releases the greenhouse gases carbon dioxide (when burned) and methane carbon dioxide (when burned) and methane (from leaks) into the troposphere.(from leaks) into the troposphere.
NATURAL GASNATURAL GAS
Some analysts see Some analysts see natural gas as the natural gas as the best fuel to help us best fuel to help us make the transition to make the transition to improved energy improved energy efficiency and greater efficiency and greater use of renewable use of renewable energy.energy.
Figure 16-11Figure 16-11
COALCOAL
Know the types and their descriptionsKnow the types and their descriptions
Figure 16-12Figure 16-12
Coal - The world’s most abundant fossil fuel
-Coal = organic matter (woody plant material) that was compressed under very high pressure to form dense, solid carbon structures– Very little decomposition occurred
A major use of coal is coal fired A major use of coal is coal fired power plants (to produce electricity)power plants (to produce electricity)They are only about 30% efficientThey are only about 30% efficient
Compare that to the efficiency of Compare that to the efficiency of photosynthesis which is about 95% photosynthesis which is about 95% efficientefficient
Coal contains impuritiesCoal contains impurities•Sulfur, mercury, arsenic, and other trace metals•Sulfur content depends on whether coal was formed in salt water or freshwater
• Coal in the eastern U.S. is high in sulfur because it was formed in marine sediments
•When high-sulfur coal is burned, it released sulfate air pollutants, which contribute to smog (fly ash and particulates) and acidic deposition •Mercury can bioaccumulate (build up in the food chains)•Ways to reduce pollution must be found
COALCOAL
Coal reserves in the United States, Russia, Coal reserves in the United States, Russia, and China could last hundreds to over a and China could last hundreds to over a thousand years.thousand years. The U.S. has 27% of the world’s proven coal The U.S. has 27% of the world’s proven coal
reserves, followed by Russia (17%), and China reserves, followed by Russia (17%), and China (13%).(13%).
In 2005, China and the U.S. accounted for 53% In 2005, China and the U.S. accounted for 53% of the global coal consumption.of the global coal consumption.
COALCOAL Coal is the most Coal is the most
abundant fossil fuel, abundant fossil fuel, but compared to oil but compared to oil and natural gas it is and natural gas it is not as versatile, has not as versatile, has a high environmental a high environmental impact, and releases impact, and releases much more COmuch more CO22 into into the troposphere.the troposphere.
Figure 16-14Figure 16-14
ENVIRONMENTAL EFFECTS OF ENVIRONMENTAL EFFECTS OF USING MINERAL RESOURCESUSING MINERAL RESOURCES
Minerals are removed through a variety of Minerals are removed through a variety of methods that vary widely in their costs, safety methods that vary widely in their costs, safety factors, and levels of environmental harm.factors, and levels of environmental harm.
A variety of methods are used based on A variety of methods are used based on mineral depth.mineral depth. Surface miningSurface mining: shallow deposits are removed.: shallow deposits are removed. Subsurface miningSubsurface mining: deep deposits are removed.: deep deposits are removed.
Open-pit MiningOpen-pit Mining
Machines dig Machines dig holes and holes and remove ores, remove ores, sand, gravel, sand, gravel, and stone.and stone.
Toxic Toxic groundwater can groundwater can accumulate at accumulate at the bottom.the bottom.
Figure 15-11Figure 15-11
Area Strip MiningArea Strip Mining
Earth movers Earth movers strips away strips away overburden, and overburden, and giant shovels giant shovels removes mineral removes mineral deposit.deposit.
Often leaves highly Often leaves highly erodible hills of erodible hills of rubble called rubble called spoil spoil banksbanks..
Figure 15-12Figure 15-12
Contour Strip MiningContour Strip Mining
Used on hilly or Used on hilly or mountainous mountainous terrain.terrain.
Unless the land is Unless the land is restored, a wall of restored, a wall of dirt is left in front dirt is left in front of a highly of a highly erodible bank erodible bank called a called a highwallhighwall..
Figure 15-13Figure 15-13
Mountaintop RemovalMountaintop Removal
Machinery Machinery removes the tops removes the tops of mountains to of mountains to expose coal.expose coal.
The resulting The resulting waste rock and waste rock and dirt are dumped dirt are dumped into the streams into the streams and valleys below.and valleys below.
Figure 15-14Figure 15-14
Mining ImpactsMining Impacts
Metal ores are Metal ores are smelted or treated smelted or treated with (potentially toxic) with (potentially toxic) chemicals to extract chemicals to extract the desired metal.the desired metal.
Laws, regulations Laws, regulations and reclamationand reclamation
Figure 15-15Figure 15-15
Combustion of fossil fuels leads to . . .Combustion of fossil fuels leads to . . .
Acid Mine DrainageAcid Mine Drainage Oil SpillsOil Spills Acid Rain (Acid Deposition)Acid Rain (Acid Deposition) Global WarmingGlobal Warming PollutionPollution Others….Others….
What is nuclear energy?What is nuclear energy?
Nuclear energy = the energy that holds Nuclear energy = the energy that holds together protons and neutrons within the together protons and neutrons within the nucleus of an atomnucleus of an atom The reaction that drives the release of nuclear The reaction that drives the release of nuclear
energy in power plants is energy in power plants is nuclear fission = the nuclear fission = the splitting apart of atomic nucleisplitting apart of atomic nuclei
Nuclear Changes: FissionNuclear Changes: Fission
Nuclear fission: Nuclear fission: nuclei of certain nuclei of certain isotopes with large isotopes with large mass numbers are mass numbers are split apart into split apart into lighter nuclei when lighter nuclei when struck by neutrons.struck by neutrons.
Figure 2-9Figure 2-9
NUCLEAR ENERGYNUCLEAR ENERGY When isotopes of uranium and plutonium When isotopes of uranium and plutonium
undergo controlled nuclear fission, the resulting undergo controlled nuclear fission, the resulting heat produces steam that spins turbines to heat produces steam that spins turbines to generate electricity.generate electricity. Uranium is found naturally in the Earth’s crustUranium is found naturally in the Earth’s crust
• It is usually in in oxide form (combined with oxygen)It is usually in in oxide form (combined with oxygen)• It must be mined – UIt must be mined – U235235 is not common the most common is not common the most common
isotope (.7204%)isotope (.7204%)• It degrades naturally and one of the nuclides it forms It degrades naturally and one of the nuclides it forms
during its degradation is Radon which is carcinogenicduring its degradation is Radon which is carcinogenic Plutonium was once found naturally but now it is Plutonium was once found naturally but now it is
produced in the nuclear reactorsproduced in the nuclear reactors
Nuclear power is an extremely rich energy source.Nuclear power is an extremely rich energy source. One gram of Uranium-235 delivers as much One gram of Uranium-235 delivers as much
energy as 3.5 metric tons of coal!!!energy as 3.5 metric tons of coal!!! One in every 5 houses in the U.S. is supplied with One in every 5 houses in the U.S. is supplied with
nuclear energy.nuclear energy. A breeder reactor is a nuclear reactor that A breeder reactor is a nuclear reactor that
produces more material to undergo fissionproduces more material to undergo fission The big environmental problem is how to dispose The big environmental problem is how to dispose
of radioactive waste (any radioactive material can of radioactive waste (any radioactive material can damage living tissue)damage living tissue)
Case Study: The Chernobyl Nuclear Case Study: The Chernobyl Nuclear Power Plant AccidentPower Plant Accident
The world’s worst nuclear power plant The world’s worst nuclear power plant accident occurred in 1986 in Ukraine.accident occurred in 1986 in Ukraine.
The disaster was caused by poor reactor The disaster was caused by poor reactor design and human error.design and human error.
By 2005, 56 people had died from radiation By 2005, 56 people had died from radiation released.released. 4,000 more are expected from thyroid cancer and 4,000 more are expected from thyroid cancer and
leukemia.leukemia. Three Mile Island in Pa was the site of Three Mile Island in Pa was the site of
“accident” in the US (not bad)“accident” in the US (not bad)
NUCLEAR ENERGYNUCLEAR ENERGY
When a nuclear reactor reaches the end of When a nuclear reactor reaches the end of its useful life, its highly radioactive materials its useful life, its highly radioactive materials must be kept from reaching the environment must be kept from reaching the environment for thousands of years.for thousands of years.
At least 228 large commercial reactors At least 228 large commercial reactors worldwide (20 in the U.S.) are scheduled for worldwide (20 in the U.S.) are scheduled for retirement by 2012.retirement by 2012. Many reactors are applying to extent their 40-Many reactors are applying to extent their 40-
year license to 60 years.year license to 60 years. Aging reactors are subject to embrittlement and Aging reactors are subject to embrittlement and
corrosion.corrosion.
NUCLEAR ENERGYNUCLEAR ENERGY Scientists disagree about the best methods Scientists disagree about the best methods
for long-term storage of high-level radioactive for long-term storage of high-level radioactive waste:waste: Bury it deep underground.Bury it deep underground. Shoot it into space.Shoot it into space. Bury it in the Antarctic ice sheet.Bury it in the Antarctic ice sheet. Bury it in the deep-ocean floor that is geologically Bury it in the deep-ocean floor that is geologically
stable.stable. Change it into harmless or less harmful isotopes.Change it into harmless or less harmful isotopes.
It is normally stored at the reactor sites.It is normally stored at the reactor sites.