Earth and Space Science Ms. Pollock 2010 - 2011 Nonrenewable Energy

Nonrenewable Energy Many of Earth’s resources used to generate electricity Energy used for transportation, manufacturing, and other necessities of life Nonrenewable resources – energy resources that exist in limited amounts and that cannot be replaced quickly once they are used

Nonrenewable energy

Fossil fuels Some of most important nonrenewable resources buried within Earth’s crust Coal Petroleum Natural gas Formed from remains of living things Fossil fuels – compounds of hydrogen and carbon (hydrocarbons) formed from the remains of plants and animals

Fossil fuels Contain stored energy originally obtained from sun Require millions of years to develop Chemical bonds broken to release energy

Formation of coal Most commonly burned fossil fuel Formed from plants that have undergone carbonization Partially decomposed plant matter buried in swamp mud becomes peat. Peat is consumed by bacteria, and methane is released, along with carbon dioxide. Happens only if oxygen absent

Formation of coal Peat Lignite Bituminous coal anthracite

Types of coal deposits Peat is covered by layers of sediment and water and gases squeezed out. Increased temperature and pressure from additional sediments further compresses lignite. Folding of Earth’s crust produces higher temperatures and pressures to change bituminous coal to anthracite.

Formation of coal

Formation of petroleum and natural gas Microorganisms and plants died in shallow prehistoric oceans and lakes. Remains fell to the bottom of the bodies of water and were covered with sediment. Heat and pressure from the layers of sediment over millions of years produce petroleum and natural gas. Mixtures of hydrocarbons Petroleum liquid Natural gas

Petroleum and natural gas

Petroleum and natural gas deposits Important energy sources for transportation, farming, industry Most often mined from permeable sedimentary rocks covered with cap rocks Natural gas usually on top because of low density

Oil traps Geologists searching for rock structures that may trap oil or gas Petroleum and natural gas flow to the surface when a well is drilled

Fossil-fuel supplies Crude oil – unrefined petroleum Main source of energy Used in production of industrial products Plastics Synthetic fabrics Medicines Waxes Synthetic rubber Insecticides Chemical fertilizers Detergents shampoos

Fossil-fuel supplies – crude oil

Fossil-fuel supplies Coal most abundant in world Found on every continent, but most found in US, Russia, and China Most coal deposits believed to have been discovered

Fossil-fuel supplies - coal

Fossil-fuel supplies Scientists believe there are undiscovered natural gas reserves. There is also an abundant material called oil shale, which contains petroleum. Cost of mining oil shale much greater than that of mining oil from sedimentary rocks

Fossil-fuel supplies – Gas and shale

Nuclear energy Discovery of smaller parts within atom led to discovery of nuclear fission Ernest Rutherford first studied and explained the result of bombarding nuclei with high-energy particles. Within 30 years, nuclear weapons and energy were developed.

Nuclear energy

Nuclear fission Splitting nuclei of heavy atoms into two or more smaller nuclei Nuclear forces 1,000,000 tunes stronger than chemical bonds, but can be split with free neutrons Chain reaction begun when a neutron hits and atom and begins an on-going reaction

Nuclear fission

How fission generates electricity Chain reactions controlled in correctly functioning nuclear power plants Reaction carried out in nuclear reactor Huge energy released from small atoms Pellets of enriched uranium used to create uranium rods Rods pelted with neutrons and become hot Water pumped over rods to cool, and steam created to run turbines

How fission generates electricity

Advantages and disadvantages of nuclear fission No air pollution Waste carried away for storage in one of three US facilities Inexpensive electricity production, after construction costs Disadvantages Produces radioactive materials with long half-lives Necessary to store waste High doses of radiation give off that destroy plant and animal tissue

Nuclear fusion Nuclear fusion – nuclei of hydrogen atoms combine to form larger nuclei of helium System that fuels sun to 15,000,000C Over 40 years of attempts to harness nuclear fusion Hope to use hydrogen atoms from ocean water for almost limitless energy By-products helium nuclei, which are harmless

Nuclear fusion