EARTH & SPACE EARTH & SPACE SCIENCESCIENCE

Chapter 7 Resources and EnergyChapter 7 Resources and Energy

7.2 Nonrenewable Resources7.2 Nonrenewable Resources

7.2 Nonrenewable Resources 7.2 Nonrenewable Resources ObjectivesObjectives

Explain why coal is a fossil fuel.Explain why coal is a fossil fuel. Describe how petroleum and natural gas Describe how petroleum and natural gas

form and how they are removed from the form and how they are removed from the Earth.Earth.

Summarize the processes of nuclear Summarize the processes of nuclear fission and nuclear fusion.fission and nuclear fusion.

Explain how nuclear fission generates Explain how nuclear fission generates electricity.electricity.

Fossil FuelsFossil Fuels

Nonrenewable resources are resources that Nonrenewable resources are resources that form at a rate that is much slower than the rate form at a rate that is much slower than the rate at which it is consumed.at which it is consumed.

A fossil fuel is a nonrenewable energy source A fossil fuel is a nonrenewable energy source that formed form the remains of organisms that that formed form the remains of organisms that lived long ago.lived long ago.

Petroleum, coal, and natural gas are fossil fuels.Petroleum, coal, and natural gas are fossil fuels. Fossil fuels are made primarily from Fossil fuels are made primarily from

hydrocarbons.hydrocarbons.

Fossil FuelsFossil Fuels

The energy contained in hydrocarbons is in the The energy contained in hydrocarbons is in the form of the bonds between the hydrogen and the form of the bonds between the hydrogen and the carbon atoms.carbon atoms.

The hydrocarbons represent chemical energy The hydrocarbons represent chemical energy that was formed in organisms millions of years that was formed in organisms millions of years ago from sunlight being captured and converted.ago from sunlight being captured and converted.

Coal is the most commonly burned fossil fuel.Coal is the most commonly burned fossil fuel. Coal is the concentrated remains of plants that Coal is the concentrated remains of plants that

have gone through carbonization.have gone through carbonization.

Fossil FuelsFossil Fuels

In the process of carbonization, partially In the process of carbonization, partially decomposed plant matter is buried in mud decomposed plant matter is buried in mud and becomes peat.and becomes peat.

Bacterial decomposition continues to Bacterial decomposition continues to release methane and carbon dioxide.release methane and carbon dioxide.

As gases escape, the concentration of As gases escape, the concentration of remaining hydrocarbons increases.remaining hydrocarbons increases.

The process of carbonization occurs in the The process of carbonization occurs in the absence of oxygen.absence of oxygen.

Fossil FuelsFossil Fuels

As peat is buried and loses water and gas As peat is buried and loses water and gas content, it becomes lignite.content, it becomes lignite.

Lignite may be further compressed into Lignite may be further compressed into bituminous coal.bituminous coal.

If enough temperature and pressure is applied to If enough temperature and pressure is applied to bituminous coal, it may become anthracite.bituminous coal, it may become anthracite.

The energy found in these products increases The energy found in these products increases as the transformation is made from peat, to as the transformation is made from peat, to lignite, to bituminous coal, to anthracite.lignite, to bituminous coal, to anthracite.

http://www.stovesonline.co.uk/how-coal-formed.html

Fossil FuelsFossil Fuels

Microorganisms and plants, as they would die, Microorganisms and plants, as they would die, they would accumulate on the bottom of lakes they would accumulate on the bottom of lakes and oceans and become buried in sediment.and oceans and become buried in sediment.

Heat and pressure would gradually increase with Heat and pressure would gradually increase with the accumulation of more and more sediment the accumulation of more and more sediment overburden.overburden.

Millions of years of heat and pressure result in Millions of years of heat and pressure result in chemical changes that convert those remains chemical changes that convert those remains into petroleum and natural gas.into petroleum and natural gas.

Both petroleum and natural gas are rich in Both petroleum and natural gas are rich in hydrocarbons.hydrocarbons.

Fossil FuelsFossil Fuels

Transportation, farming, and many other Transportation, farming, and many other industries rely on fossil fuels.industries rely on fossil fuels.

Petroleum and natural gas are often taken from Petroleum and natural gas are often taken from permeable sedimentary rocks.permeable sedimentary rocks.

Pressure forces fluids (including oil and gas) up Pressure forces fluids (including oil and gas) up through permeable rocks.through permeable rocks.

When the fluids reach an impermeable cap rock, When the fluids reach an impermeable cap rock, they accumulate in a reservoir and become they accumulate in a reservoir and become stratified according to density.stratified according to density.

http://www.utexas.edu/depts/grg/huebner/Spring2003/grg306c/Coal_Oil.htm

http://www.uwsp.edu/geo/faculty/ozsvath/images/oil_and_gas_reservoirs.htm

Fossil FuelsFossil Fuels

Geologists look for Geologists look for structures that would structures that would trap oil and gas.trap oil and gas.

If a well is drilled into If a well is drilled into a reservoir, oil and a reservoir, oil and gas are often forced gas are often forced to the surface by to the surface by pressure.pressure.

http://www.uwsp.edu/geo/faculty/ozsvath/images/oil_gusher.htm

Fossil Fuel SuppliesFossil Fuel Supplies

Fossil fuels, though a nonrenewable resource, Fossil fuels, though a nonrenewable resource, are a major source of energy globally.are a major source of energy globally.

Crude oil is also used in the production of Crude oil is also used in the production of plastics, medicines, synthetic fabrics, waxes, plastics, medicines, synthetic fabrics, waxes, synthetic rubber, insecticides, chemical synthetic rubber, insecticides, chemical fertilizers, shampoos, detergents, and other fertilizers, shampoos, detergents, and other products.products.

Coal is globally the most abundant fossil fuel.Coal is globally the most abundant fossil fuel. The United States, Russia, and China have two-The United States, Russia, and China have two-

thirds of the known coal reserves globally.thirds of the known coal reserves globally.

Fossil Fuel SuppliesFossil Fuel Supplies

It is likely that most of It is likely that most of the petroleum the petroleum reserves on Earth reserves on Earth have been have been discovered.discovered.

Many new gas Many new gas reserves are likely to reserves are likely to be discovered and be discovered and much oil shale still much oil shale still lies beneath Earth’s lies beneath Earth’s surface.surface. http://origin.mars5.jpl.nasa.gov/

classroom/schoolhouse/rocklibrary/index3.html

http://www.mines.edu/research/ceri/oil%20shales.html

Nuclear EnergyNuclear Energy Nuclear energy is energy produced by manipulation of Nuclear energy is energy produced by manipulation of

the nuclei of atoms – matter contains a great deal of the nuclei of atoms – matter contains a great deal of energy.energy.

Nuclear fission is the process in which the nucleus of a Nuclear fission is the process in which the nucleus of a large atom is split into two or more fragments releasing large atom is split into two or more fragments releasing neutrons and energy.neutrons and energy.

The forces that hold the nucleus of an atom together are The forces that hold the nucleus of an atom together are about a million times stronger than the chemical bonds about a million times stronger than the chemical bonds between atoms.between atoms.

A neutron is fired into the nucleus of a large atom to A neutron is fired into the nucleus of a large atom to cause a split releasing energy and other neutrons that cause a split releasing energy and other neutrons that may split other atoms.may split other atoms.

The result is a chain reaction.The result is a chain reaction.

http://library.thinkquest.org/C003730/index.php3?ID=18

http://www.uraniumminerals.com/UTh/U

Nuclear EnergyNuclear Energy

An uncontrolled chain An uncontrolled chain reaction results in an reaction results in an explosion – like an explosion – like an atomic bomb.atomic bomb.

Controlled nuclear Controlled nuclear fission can be used to fission can be used to generate electricity.generate electricity.

http://www.digitalhistory.uh.edu/do_history/decisions/hiroshima.html

Nuclear EnergyNuclear Energy An enriched fuel source, typically uranium 235, is formed An enriched fuel source, typically uranium 235, is formed

into pellets and contained in fuel rods.into pellets and contained in fuel rods. The fuel rods are housed in the reactor core which also The fuel rods are housed in the reactor core which also

contains control rods that contain cadmium or boron (for contains control rods that contain cadmium or boron (for absorbing neutrons) which are used to slow down the absorbing neutrons) which are used to slow down the chain reaction.chain reaction.

The plant “powers up” to increase the heat by allowing The plant “powers up” to increase the heat by allowing the reaction to occur more freely and “powers down” to the reaction to occur more freely and “powers down” to slow the reaction and cool the reactor.slow the reaction and cool the reactor.

Water is pumped around the fuel rods to absorb the heat Water is pumped around the fuel rods to absorb the heat and then routed to a second circuit where the heat is and then routed to a second circuit where the heat is transferred to water in the secondary unit to produce transferred to water in the secondary unit to produce steam.steam.

Nuclear EnergyNuclear Energy

The steam is then used to turn the The steam is then used to turn the turbines of electrical generators.turbines of electrical generators.

A third circuit of water carries away the A third circuit of water carries away the excess heat and cools the water before it excess heat and cools the water before it can be released into the environment.can be released into the environment.

If the water is too hot when it is released If the water is too hot when it is released into the environment, it is considered to be into the environment, it is considered to be thermal pollution.thermal pollution.

Nuclear EnergyNuclear Energy

Advantages of nuclear fission power plants.Advantages of nuclear fission power plants. No air pollutionNo air pollution More uranium than oil availableMore uranium than oil available Reduced dependence on foreign oilReduced dependence on foreign oil Building new plants = jobsBuilding new plants = jobs

Disadvantages of nuclear fission power plants.Disadvantages of nuclear fission power plants. Radioactive waste productsRadioactive waste products Security of waste products and fuel sourceSecurity of waste products and fuel source Expensive to buildExpensive to build Currently there are only three disposal facilities in the Currently there are only three disposal facilities in the

U.S. – much of the nuclear waste is stored in onsite U.S. – much of the nuclear waste is stored in onsite water poolswater pools

http://www.uni.edu/darrow/wind

Nuclear EnergyNuclear Energy

Nuclear fusion is the process by which the nuclei Nuclear fusion is the process by which the nuclei of small atoms are joined together to form a of small atoms are joined together to form a new, more massive nucleus.new, more massive nucleus.

Nuclear fusion is the process that powers stars Nuclear fusion is the process that powers stars as hydrogen nuclei fuse to form helium nuclei.as hydrogen nuclei fuse to form helium nuclei.

Fusion reactions require temperatures over Fusion reactions require temperatures over 15,000,000 15,000,000 °C to occur.°C to occur.

If scientists can figure out how to control such a If scientists can figure out how to control such a high energy environment, hydrogen from ocean high energy environment, hydrogen from ocean water could be a fuel source with helium as the water could be a fuel source with helium as the waste product.waste product.