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Chapter 12

Nonrenewable Energy Sources

Warm-Up Question

What have you done today that required energy?

Measuring Energy

• Are all energy sources measured in the same way?– Gallons of gasoline– Cords of wood– Cubic feet of natural gas

• How do we measure the amount of energy if each source has its own unit of measure?

British Thermal Units

• 1 Btu = amount of energy needed to raise the temperature of 1 lb. of water by 1 degree Fahrenheit

• 1 wooden kitchen match = 1 Btu

• 1 ounce of gasoline = 1,000 Btu’s

Btu’s

• Everyday, the average American uses about 890,000 Btu’s of energy

• In order to measure very large quantities of energy, we use the “quad”, which represents 1 quadrillion (1,000,000,000,000,000) Btu’s

• The U.S. uses about 1 quad of energy every 3.7 days

Energy

• What is the difference between renewable and nonrenewable energy sources?

• What percent of our energy comes from nonrenewable energy sources? Renewable energy sources?

Nonrenewable Energy

• Nonrenewable energy resources - fossil fuels (coal, oil, natural gas) and nuclear fuels

U.S. Energy Consumption(2011)

Oil37%

Gas26%

Coal20%

Nuclear8%

Renewable9%

Source: Energy Information Agency

Energy Consumption in the U.S.

Energy Use

• Commercial energy sources - those that are bought and sold, such as coal, oil and natural gas

• Subsistence energy sources - those gathered by individuals for their own use such as wood, charcoal, and animal waste

Process of Energy Use

Efficiency of U.S. Automobiles

• How has automobile efficiency changed over the past 30 years?

Efficiency of U.S. Automobiles

AP Practice Problem

Which of the following is not a nonrenewable energy resource?

A. Oil

B. Coal

C. Natural gas

D. Wind

E. Nuclear fuels

Electricity Generation

• The burning fuel from coal transfers energy to water, which becomes steam

• The kinetic energy contained within the steam is transferred to the blades of a turbine, a large device that resembles a fan

• As the energy in the steam turns the turbine, the shaft in the center of the turbine turns the generator

• This mechanical motion generates electricity

Electricity Generation

AP Practice Problem

Which of the following is not a nonrenewable energy resource?

A. Oil

B. Coal

C. Natural gas

D. Wind

E. Nuclear fuels

Fuels Used for Electricity Generation in the U.S.

• Most coal burning power plants are about 35% efficient

Cogeneration

• Cogeneration - using a fuel to generate electricity and to produce heat– Ex: If steam is used for industrial purposes or

to heat buildings it is diverted to turn a turbine first

• This improves the efficiency to as high as 90%

Coal

• Coal - a solid fuel formed primarily from the remains of trees, ferns, and other plant materials that were preserved 280-360 million years ago

• Four types of coal ranked from lesser to greater age, exposure to pressure, and energy content

• These four types are: lignite, sub-bituminous, bituminous, and anthracite

• The largest coal reserves are in the United States, Russia, China, and India

Coal

Coal

• Coal is most abundant fossil fuel– Primarily used for generating

electricity

• There are 3 categories of coal:– Lignite – least desirable because of

its high moisture content– Bituminous – most widely used

because it is most abundant and easiest to mine

– Anthracite – has the highest energy content and is cleanest burning, but is hard to obtain

Coal

Coal Reserves in the U.S.

anthracite

bituminous

lignite

Coal in the World

• Where in the world is coal found?

Advantages and Disadvantages of Coal

Advantages Disadvantages

Energy-dense Contains impurities

Plentiful Release impurities into air when burned

Easy to exploit by surface mining Trace metals like mercury, lead, and arsenic are found in coal

Technological demands are small Combustion leads to increased levels of sulfur dioxide and other air pollutants into the atmosphere.

Economic costs are low Ash is left behind

Easy to handle and transport Carbon is released into the atmosphere which contributes to climate change

Needs little refining

Petroleum (Oil)

• Petroleum - a mixture of hydrocarbons, water, and sulfur that occurs in underground deposits

• Oil and gasoline make this ideal for mobile combustion, such as vehicles

• Formed from the remains of ocean-dwelling phytoplankton that died 50-150 million years ago

• Countries with the most petroleum are Saudi Arabia, Russia, the United States, Iran, China, Canada, and Mexico

Petroleum

Oil in the U.S.

• When was the first U.S. commercial oil well drilled?– 1859

• Where was it drilled?– Titusville, PA

What are the top oil producing states in the

U.S.?

• Texas (21%)• Alaska (11%)• California (10%)• North Dakota (6%)• Louisiana (3%)

Issues Related to the Use of Oil

• Present technology only removes 1/3 of an oil deposit

• Secondary recovery methods are used to recover more oil, such as forcing water or gas into wells to drive the oil out

• As oil prices increase, more expensive and aggressive secondary recovery methods will need to be used

Oil Drilling

Oil Derrick - starts the well

Pump - removes oil from ground

Oil Pump

Secondary Recovery

• Steam can be injected to recover more oil

Petroleum Products

• What products can be made from petroleum?

Which countries are in OPEC?

Benefits of Using Oil

• Oil is more concentrated than coal, burns cleaner, and is easily transported through pipelines

• Can be used to make many products

• It causes less environmental damage than coal mining

Drawbacks of Using Oil

• Oil spills

• Oil well blowouts

• Pipelines and transportation routes

• Air pollution when burned

Price of Oil per Barrel (U.S.)

Price of Gasoline in the United States

0

1

2

3

4

5

Jan-00 May-01 Sep-02 Feb-04 Jun-05 Nov-06 Mar-08 Aug-09 Dec-10 Apr-12

Time (months)

Ret

ail P

rice

($/g

allo

n)

Source: Energy Information Agency

What we pay for in a gallon of gasoline

Source: Energy Information Agency

Advantages and Disadvantages of Petroleum

Advantages Disadvantages

Convenient to transport and use Releases carbon dioxide into atmosphere

Relatively energy-dense Possibility of leaks when extracted and transported

Cleaner-burning than coal

Releases sulfur, mercury, lead, and arsenic into the atmosphere when burned

Natural Gas

• Natural gas - exists as a component of petroleum in the ground as well as in gaseous deposits separate from petroleum

• Contains 80-95% methane and 5-20% ethane, propane, and butane

Where in the world is Natural Gas?

Advantages and Disadvantages of Natural Gas

Advantages Disadvantages

Contains fewer impurities and therefore emits almost no sulfur dioxide or particulates

When unburned, methane escapes into the atmosphere

Emits only 60% as much carbon dioxide as coal

Exploration of natural gas has the potential of contaminating groundwater

Other Fossil Fuels

• Oil sands - slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay

• Bitumen (tar or pitch) - a degraded type of petroleum that forms when a petroleum migrates close to the surface, where bacteria metabolize some of the light hydrocarbons and others evaporate

Hubbert Curve

• Hubbert curve - a graph that shows the point at which world oil production would reach a maximum (“peak oil”) and the point at which we would run out of oil

Future Use of Fossil Fuel Use

• If current global use continues, we will run out of conventional oil in less than 40 years

• Coal supplies will last for at least 200 years, and probably much longer

Nuclear Energy

• Nuclear Fission - a nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts

Uranium

Uranium Ore • 99.3% of all uranium

atoms are the isotope U-238

• Remaining 0.7% are U-235

Fuel Pellets• U-235 is more desirable

because it’s easier to split (fission)

• Enrichment process increases the amount of U-235

Fission

• A nuclear power plant converts the energy contained within the nuclei of atoms into electrical energy

• U-235 absorbs a neutron to become highly unstable U-236

• U-236 splits and releases a tremendous amount of heat energy

Nuclear Fission

Nuclear Reactors

Nuclear Reactors

• Fuel rods - the cylindrical tubes that house the nuclear fuel used in a nuclear power plant

• Nuclear power plants work by using heat from nuclear fission to heat water

• This water produces the steam to turn the turbine, which turns a generator

• Control rods - cylindrical devices that can be inserted between the fuel rods to absorb excess neutrons, thus slowing or stopping the fission reaction

Nuclear Energy in the World

• Nuclear power plants generate about 22% of the United States’ electricity

• In comparison:– 75% in France– 46% in Sweden– 43% in Ukraine– 39% in South Korea– 30% in Germany– 30% in Japan

Nuclear Power Plants in the U.S.

Nuclear Power Plant Meltdowns

• In 1986, the Chernobyl (Ukraine) nuclear reactor exploded

• 50 tons of radioactive material spewed into the surrounding area, contaminating millions of acres of forest.

• Forced the evacuation of at least 30,000 people

• Eventually caused thousands to die from cancer and other illnesses

Nuclear Waste

• Radioactive waste - once the nuclear fuel can not produce enough heat to be used in a power plant but it continues to emit radioactivity

• This waste must be stored in special, highly secure locations because of the danger to living organisms

Nuclear Waste

• High-level radioactive waste - the form used in fuel rods

• Low-level radioactive waste - the protective clothing, tools, rags, and other items used in routine plant maintenance

Nuclear Fusion

• Nuclear fusion - occurs when lighter nuclei are forced together to produce heavier nuclei and heat is released– Ex: the reaction that powers the Sun and

other stars

• Fusion is a promising, unlimited source of energy in the future, but so far scientists have had difficulty containing the heat that is produced

Advantages and Disadvantages of Nuclear Energy

Advantages Disadvantages

No air pollution is produced Possibility of accidents

Countries can limit their need for imported oil

Disposal of the radioactive waste

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