Fossil fuels What are fossil fuels? –Natural resources that is made of once living organic matter that changed into Coal, Oil or Natural gas. Stored solar.
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Fossil fuels
• What are fossil fuels?– Natural resources that is
made of once living organic matter that changed into Coal, Oil or Natural gas.
• Stored solar energy– “Ancient Sunlight”
• Fossil fuels provide energy for automobiles, ships, planes and operate factories.
• Limited supply of ENERGY
Pro’s & Con’s of Fossil Fuels• 4 main purposes
– Transportation– Manufacturing– Heating/cooling– Electricity
• Problem with fossil fuels;– Limited resources– Environmental
consequences
Electricity • Most convenient form of
energy to use.• Used world wide in any
application.• Advantages
– Transported across large areas inexpensively.
– Readily available
• Disadvantages– Other energy sources used
to produce it– Difficult to store– Aging infrastructure
Creation of electricity• Electric generator - converts mechanical
energy into electrical energy.
• Function 1. Burning of fossil fuels or the fission of uranium to
boil H2O to create steam
2. Steam turns turbine blades
3. Turbine is connected to a generator where electrical energy is created.
Fossil fuel Heat Mechanical energy
Electricity
Usage of energy • People in developed
societies use more energy than people in developing countries do.
• The United States uses more energy per person than any other country except Canada and the United Arab Emirates.
• Countries with limited fossil fuels, use other sources of energy, such as hydroelectric or nuclear power.
Formation of Coal• Coal forms from the remains of plants that lived in swamps
hundreds of millions
of years ago.– Formation of coal – animation– Formation of fossil fuels
• Oil and natural gas result from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago.
Types of coal• Anthracite• Anthracite is coal with the highest carbon content, between 86 and 98 percent, and a heat value of
nearly 15,000 BTUs-per-pound. Most frequently associated with home heating, anthracite is a very small segment of the U.S. coal market. There are 7.3 billion tons of anthracite reserves in the United States, found mostly in 11 northeastern counties in Pennsylvania.
• Bituminous• The most plentiful form of coal in the United States, bituminous coal is used primarily to generate
electricity and make coke for the steel industry. The fastest growing market for coal, though still a small one, is supplying heat for industrial processes. Bituminous coal has a carbon content ranging from 45 to 86 percent carbon and a heat value of 10,500 to 15,500 BTUs-per-pound.
• Subbituminous• Ranking below bituminous is subbituminous coal with 35-45 percent carbon content and a heat value
between 8,300 and 13,000 BTUs-per-pound. Reserves are located mainly in a half-dozen Western states and Alaska. Although its heat value is lower, this coal generally has a lower sulfur content than other types, which makes it attractive for use because it is cleaner burning.
• Lignite• Lignite is a geologically young coal which has the lowest carbon content, 25-35 percent, and a heat
value ranging between 4,000 and 8,300 BTUs-per-pound. Sometimes called brown coal, it is mainly used for electric power generation.
3 main Grades of Coal
• Anthracite – hard coal – high carbon (100%) low sulfur – high grade coal – home heating coal
• Bituminous – mid grade – high carbon (85%) high sulfur – make electricity and coke for steel industry, Mainly in U.S.
• Lignite – brown coal – high sulfur and low carbon (50%) – used by electric power plants - aka soft coal
Coal mining• Most of the world’s fossil-fuel reserves are made
up of coal.• Coal is relatively inexpensive and it needs little
refining after being mined.• Asia and North America are particularly rich in
coal deposits.• Over half the electricity generated in the United
States comes from coal-fired power plants.• World uses 5 Billion metric tons yearly, reserves
could last at least 200 years.• Sulfur is found in all grades of coal, major source
of pollution when burned, acid rain.
2 basic ways to mine coal
• Surface – removal of minerals and metals in the Earth’s surface.
• Inexpensive and safer• Destroys habitat, environment
– Strip mines– Mountain top– Open pit– Quarry
•
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Formation of Oil & Gas
• Micro-organisms (not dinosaurs) collect at the bottom of shallow seas
• Heat, pressure and millenia convert to oil droplet.
• Lifting and folding of the earth’s crust concentrates the oil and gas into an extractable location.
Oil – Petroleum – a.k.a. Crude oil• 45% of petroleum is used
in commercial energy• Crude oil is liquid
hydrocarbons, major energy source
• Products made from oil: Plastics, fuels and chemicals
• Oil is trapped in faults, folds and salt domes
• Most of the world’s oil reserves are in the Middle East, smaller one located in the U.S., Venezuela, Nigeria
World Oil Reserves• Most of the world’s oil
reserves are in the Middle East, smaller one located in the U.S., Venezuela, Nigeria
Disadvantages of oil• Oil spills from tanker ships are another potential environmental
problem of oil use.– Double hulls are now used.
• More oil pollution comes from everyday sources, like leaking cars, throwing away of oil products.
Natural gas• 20% of worlds natural resources• Stored for use as a fuel.
– Once was considered a waste product of oil production.• Nat. Gas contains;
– Methane gas CH4
– Ethene gas C2H5
– Propane C3H8
– Butane C4H10
• produces less pollutants than other fossil fuels when burned• Current reserves, 100 million metric tons, last approx. 100 years• NEW Technology – Shale gas has greatly increased supply
Nuclear energy• FYI - In the 1950s and 1960s, nuclear power plants
were seen as the power source of the future because the fuel they use is clean and plentiful.
• FYI - In the 1970s and 1980s, however, many planned nuclear power plants were cancelled and others under construction were abandoned.
• Seen as cheap alternative to fossil fuels.• Today, nuclear power accounts for 17% of the world’s
electricity.
How nuclear energy works• Nuclear energy is the energy released by a
fission or fusion reaction.
• In nuclear power plants, atoms of the element uranium-235 are used as the fuel.
• The nuclei of uranium atoms are bombarded with atomic particles called neutrons.
• These collisions cause the nuclei to split in a process called nuclear fission.
Coal Petroleum Natural Gas
22% 43% 20%
Fossilized plant material preserved in sediments and altered by geological forces that condense into a carbon rich fuel.
Plankton at the bottom of shallow seas, buried millions of years ago in sediment, converted to hydrocarbons. Geologic activity bends, folds rocks and concentrates the hydrocarbons for extraction.
Plankton at the bottom of shallow seas, buried millions of years ago in sediment, converted to hydrocarbons. Geologic activity bends, folds rock and concentrates the hydrocarbons for extraction.
Electricity Transportation, petrochemical industry
Home heating, industry feed stock
36% Europe Eurasia30% Asia Pacific26% North America6% Africa and Middle East 2% Central and South America
61% Middle East14% Other 13% Canada7% Venezuela3% Nigeria
40.8% Middle East26.7% Russia16.4% Europe/Asia 8.3% Americas7.8% Africa
Destroys mountain tops, burying forests, streams, farms, and houses.
Oil wells are dirty and disruptive and cause poor air quality.
Toxic gases are released.
Poisonous and explosive gases and release of radioactivity, mercury.
CO2 emissions, global climate change, small amount of CO2 emissions.
CO2 is released. It is the cleanest of the 3.
Clean coal technology. Oil shale, tar sand. Methane Hydrate, garbage and manure digesters, shale deposits.
• Nuclear fission releases a tremendous amount of energy and more neutrons, which in turn collide with more uranium nuclei.
• The heat released during nuclear reactions is used to generate electricity in the same way that power plants burn fossil fuels to generate electricity.
Nuclear energy advantages disadvantages
• Non air producing pollutants.
• Fuel source is very compact.
• Properly maintained, very safe to operate
• Expensive to build, operate and maintain.
• Storing of nuclear waste, geologically stable
• Safety concerns– Chernobyl 1986– Three mile island 1979
Future of nuclear power
• Nuclear fusion – Combining of two elements (deuterium,
tritium) to form helium– Produce large amounts of energy– Produce less amount of radioactive waste– Difficult to control the production and process– Same process occurs in stars
• Wolf creek nuclear power plant
• Burlington, Ks – coffey county
• Began operations 1985
• 1.2 megawatts of electricty– 800,000 homes
• ldks
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Coal
Ample supply
High net energyyield
Very high airpollution
High CO2
emissions
65,000 to 200,000deaths per yearin U.S.
High land disruption fromsurface mining
High land use
Low cost (with huge subsidies)
Nuclear
Ample supplyof uranium
Low net energyyield
Low air pollution(mostly from fuelreprocessing)
Low CO2
emissions(mostly from fuelreprocessing)
About 6,000deaths per year in U.S.
Much lower landdisruption fromsurface mining
Moderate land use
High cost (with huge subsidies)
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Periodic removaland storage of
radioactive wastesand spent fuel assemblies
Periodic removaland storage of
radioactive liquid wastes
Pump
Steam
Small amounts of radioactive gases
Water
Black
Turbine Generator
Waste heat Electrical power
Hot water output
Condenser
Cool water input
Pump
Pump Wasteheat
Useful energy25 to 30%
WasteheatWater source
(river, lake, ocean)
Heatexchanger
Containment shell
Uranium fuel input(reactor core)
Emergency corecooling system
Controlrods
Moderator
Pressurevessel
Shielding
Coolantpassage
CoolantCoolant
Hot coolantHot coolant
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Front end Back end
Uranium mines and millsOre and ore concentrate (U3O8)
Geologic disposalof moderate-and high-levelradioactive wastes
High-levelradioactivewaste orspent fuelassemblies
Uranium tailings(low level but long half-life)
Conversion of U3O8
to UF6
Processeduranium ore
Uranium-235 as UF6
Enrichment UF6
EnrichedUF6
Fuel fabrication
Spent fuelreprocessing
Plutonium-239as PuO2
(conversion of enriched UF6 to UO2
and fabrication of fuel assemblies)
Fuel assemblies Reactor Spent fuel assemblies
Interim storageunder water
Open fuel cycle today
Prospective “closed” end fuel cycle
Decommissioningof reactor
Decommissioningof reactor
Spent fuelassembliesSpent fuelassemblies
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Low risk of accidents because of multiple safety systems (except in 35 poorly designed and run reactors in former Soviet Union and Eastern Europe)
Moderate land use
Moderate landdisruption andwater pollution(without accidents)
Emits 1/6 asmuch CO2 as coal
Lowenvironmentalimpact (withoutaccidents)
Large fuelsupply
Spreads knowledge and technology for building nuclear weapons
No acceptable solution for long-term storage of radioactive wastes and decommissioning worn-out plants
Catastrophic accidents can happen (Chernobyl)
High environmental impact (with major accidents)
Low net energy yield
High cost (even with large subsidies)
Advantages Disadvantages
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Clay bottom
Up to 60deep trenchesdug into clay.
As many as 20flatbed trucksdeliver wastecontainers daily.
Barrels are stackedand surroundedwith sand. Coveringis mounded to aidrain runoff.
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Storage Containers
Fuel rod
Primary canister
Overpack containersealed
Underground
Buried and capped
Ground Level
Unloaded from train
Lowered down shaft
Personnal elevator
Air shaft
Nuclear waste shaft
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