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Chapter 17 1.  Energy Resources and Fossil Fuels 2.

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Presentation on theme: "Chapter 17 1.  Energy Resources and Fossil Fuels 2."— Presentation transcript:

1 Chapter 17 1

2  Energy Resources and Fossil Fuels 2

3  Fossil fuels are the remains of ancient plants and animals that changed into coal, oil, natural gas and methane hydrates (look like ice)  Two problems with fossil fuels: 1. the supply is limited and 2. obtaining and using them causes environmental problems. 3

4  Cooking  Transportation  Manufacturing  Heating and cooling  Generating electricity  The fuel we use for these purposes depends on energy content, cost, availability, safety, and by-products. 4

5  How is electricity generated?  An electric generator is a machine that converts mechanical energy (turbine) into electrical energy.  A turbine is a wheel that changes the force of a moving gas or liquid into energy. 5

6 Combustion Chamber of a Coal-Burning Power Plant Inside the combustion chamber of a coal- fired power plant burning fossil fuels release energy in the form of heat 6

7  Every product requires energy to produce.  The price of the product reflects the cost of the fuel.  Example: buying a plane ticket includes the cost of the fuel. 7

8  We use more energy per person than any other country in the world except Canada and the United Arab Emirates.  Most of the energy consumed in the United States is used for industrial purposes. 8

9 COAL FORMATION  Coal forms from the remains of plants that lived in swamps millions of years ago.  Layers of sediment compressed the plant remains; heat and pressure within the Earth’s crust caused coal to form. OIL AND NATURAL GAS FORMATION  These form from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago.  These remains were buried in sediments, heated until they became energy-rich carbon based molecules. 9

10  Most abundant fossil fuel in world  Asia and North America very rich in coal.  Inexpensive  Needs little refining 10

11  Underground mining has minimal effects on environment.  Surface mining does more damage  Move entire mountains and toxic chemical can leach into streams. 11

12  Higher-grade coals produce less pollution than lower-grade coals.  Burning any coal releases sulfur which leads to air pollution and acid precipitation.  Serious problems in China. 12

13  Oil that is pumped out of ground is called crude oil, or petroleum  Anything made from petroleum is called a petroleum product.  Examples: fuels, chemicals, plastics  Petroleum is 45% of the world’s commercial energy use. 13

14 Oil refinery An oil refinery converts petroleum into fuel. 14

15  Most oil reserves are in Middle East.  Geologist gather data  Exploration wells are drilled  If oil can be extracted at profitable rate, oil is pumped and flows to surface. 15

16  20% of the world’s nonrenewable energy comes from natural gas (methane)  Burning methane produces fewer pollutants because it burns cleaner. 16

17  Burning oil releases pollutants.  Driving cars leads to smog and health problems.  Released carbon dioxide leads to climate change.  Oil spills pollute our waters.  Remember more oil pollutes our water from daily activities. 17

18  Fossil fuels supply about 90% of the energy used in developed countries.  By 2050, the world energy demands may double (increased population and industry)  Cost of fossil fuels will increase 18

19 PREDICTING OIL PRODUCTION  Oil reserves are oil deposits that can be extracted profitably  Some oil deposits have not yet been discovered  We must also take into account changing technology  The law of supply and demand FUTURE OIL RESERVES  Some are located under the ocean, but extracting this oil is much more expensive.  Technology needs to improve and oil extracted from the ocean will cost more than oil extracted from land. 19

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21  Nuclear Energy 21

22  In 1950s and 1960s seen as power for the future  Clean and plentiful  In 1970s and 1980s, 120 nuclear power plants were cancelled  Why? 22

23  Nuclear energy is the energy contained in the nuclei of atoms.  Atoms of uranium are used as the fuel in nuclear power plants  Nuclear fission is the splitting of the atomic nuclei.  Releases a tremendous amount of energy.  New nuclei and neutrons result from this splitting. 23

24  A nuclear reactor is surrounded by a thick pressure vessel that is filled with a cooling fluid.  This vessel contains the fission products in case of any accident.  Thick concrete walls surround the reactor 24

25  Metal fuel rods containing solid uranium are bombarded with neutrons.  Chain reaction releases energy and more neutrons.  Rate of reaction is controlled in reactor. 25

26  Heat released during reaction generates electricity.  The energy heats a closed loop of water that heats another body of water.  The water boils, produces steam, and the steam drives a turbine, creating electricity. 26

27  Very concentrated  Does NOT produce greenhouse gases.  Release less radioactivity than coal-burning power plants.  France generates 3/4ths of its electricity from nuclear power and produces way less air pollution than in U.S. 27

28  Building and maintaining safe reactors is very expensive.  Cost more than $3,000 per kilowatt of electrical capacity.  Wind (less than $1,000/kilowatt)  Natural gas (less than $600/kilowatt) 28

29  Very difficult to find safe place to store nuclear waste.  Fission products remain radioactive for thousands of years.  Storage sites must be located in areas that are extremely geologically stable. 29

30  Fission process can get out of control.  Chernobyl (worst nuclear accident in the world 1986)  Three Mile Island (worst nuclear accident in U.S. 1979) 30

31 CHERNOBYL  Ukraine (1986)  All safety devices had been shut off to conduct unauthorized test.  Caused explosion that destroyed reactor.  No containment building.  Very old design.  Northern Europe and Ukraine are still contaminated THREE MILE ISLAND  Pennsylvania (1979)  Human error again  Blocked valves and broken pumps  Only small amount of radioactive gas escaped.  More than 300 safety improvements are required for new nuclear power plants. 31

32  Nuclear fusion: the combining of atomic atoms.  A safer energy source due to less radioactive byproducts.  Can release tremendous amounts of energy.  Why don’t we do it???? 32

33  Atomic nuclei must be heated to extremely high temperatures: 100 million degrees C.  Nuclei must be maintained at very high concentrations and confined.  Achieving all three of these simultaneously is extremely difficult. 33

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