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.

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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

•

Underground • Used when ore or minerals far below earth’s

surface– Heavy man labor– Mechanized labor

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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.

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Uses of Crude Oil

• 55 gallon barrel

of Oil

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

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Crude Oil and Natural Gas Pool

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

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Operational

Decommissioned

Proposed high levelnuclear waste storage site

Reactors

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World map of nuclear power plants

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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Fig. 11.2

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Fig. 11.1a

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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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Fig. 11.4

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Fig. 11.9

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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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What covers waste

Clay

Gravel

Sand

Compacted clay

Soil

Topsoil

Grass

Gravel

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Personnel elevator

Air shaft

Nuclear waste shaft

2,500 ft.(760 m)deep

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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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CO11

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Fig. 11.3

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Fig. 11.7

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Fig. 11.15

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Waste container

Steel wall

Steel wall

Severalsteel drumsholding waste

Lead shielding

2 meters wide2–5 meters high