Energy From Organic FuelsEnergy From Organic Fuels

Chapter 15Chapter 15

OpeningOpening• List the ways you depend upon energy in your

everyday lives. • Identify those activities that are dependent upon

fossil fuels. – Fossil fuels: hydrocarbon fuels formed from organic

matter.

Energy UsesEnergy Uses

• Automobiles• Planes/Jets• Trains• Household Appliances• Industry• Agriculture• Heating/Cooling Systems• Etc.

The Need for EnergyThe Need for Energy

• Fuel – is any substance from which energy can be obtained.

• To produce electricity, fuel is burned to boil water, producing steam.

• The steam exerts pressure on giant machines called turbines, causing them to turn.

Non-renewable Energy SourcesNon-renewable Energy Sources

• Non-renewable Resource: A resource that is not being replenished or formed at any significant rate on a human timescale.

Examples:• Oil• Natural Gas• Coal• Nuclear (Uranium)

HydrocarbonsHydrocarbons

• Hydrocarbon – a compound composed only of carbon and hydrogen.

• Ex. Methane, propane, butane, octane

• Fossil Fuels – Fuels derived from the remains of organisms that lived long ago.

Formation of Oil and Natural Gas Formation of Oil and Natural Gas DepositsDeposits

• Petroleum or oil is not a single chemical compound. Oil is comprised of a variety of liquid hydrocarbons.

• Oil and natural gas were formed when life in the early seas brought organic material raining down onto the seafloor faster than it could decay as sediments buried the material.

Hydrocarbon FormationHydrocarbon Formation

• As this material became buried deeper, the heat and pressure under the ground slowly cooked this organic material into oil by breaking down complex organic molecules into smaller, hydrocarbon molecules.

• Then the oil and natural gas were collected in a trap of porous sandstone or limestone, contained by an impermeable cap of shale or salt (Appenzeller, 2004).

United States Oil FactsUnited States Oil Facts

• 1 barrel of oil = 42 gallons

• The US consumes nearly 7 billion barrels of oil per year, to supply about 40% of all energy used.

• The US alone consumes 25% of the oil used worldwide.

• Over ½ of the oil consumed has been imported from other countries.

Uses of OilUses of Oil

• 2/3 of oil goes to fuel for vehicles

• Asphalt

• Hydrocarbon based fertilizers and pesticides

• Synthetic fabrics

• Plastics (Appenzeller, 2004)

Fractional

Distillation

Tower

Coal FormationCoal Formation

• Coal is formed from the remains of land plants that were rapidly deposited and buried in a swampy environment.

• The process requires anaerobic conditions, in which oxygen is absent or nearly so, since reaction with oxygen destroys the organic matter.

• It is found in sedimentary rocks in well defined beds.

Prehistoric Coal SwampPrehistoric Coal Swamp

Types of CoalTypes of Coal• Peat plant material with lots

of water and a low level of carbon.

• Lignite Soft brown coal – 40% carbon

Types of CoalTypes of Coal

• Bituminous Medium hardness ~85% C

• Anthracite Hardest coal ~95% C– As the coals become harder, the

carbon content increases, and so does the amount of heat released by burning a given weight of coal.

Coal FactsCoal Facts

• The US possess about 25% of the world’s coal reserves (270 billion tons).

• Coal currently supplies about 20% of total US energy needs.

• Coal-fired power plants account for more than half of US electric power generation.

• The US coal supply could satisfy US energy needs for more than 200 years at current levels of energy use if coal could be used for all energy purposes. (Montgomery, 2006)

Environmental Consequences of Environmental Consequences of Fossil FuelsFossil Fuels

• Coal is a very dirty fossil fuel and can have large environmental effects.– Carbon dioxide– Sulfur– Ash– Coal mining hazards

• Methane is a greenhouse gas.

• Motor vehicles emit carbon oxides, nitrogen oxides, sulfur oxides, and fine particulates.

Fossil Fuel ReservesFossil Fuel Reserves

Nuclear EnergyNuclear Energy• Nuclear Fission is the splitting apart of atomic

nuclei into smaller ones with the release of energy.

• The fissionable nucleus used most in modern nuclear reactors is the isotope uranium-235.

• Worldwide, 95% of known uranium reserves are found in sedimentary rocks.

• The rare isotope U-235 is in such short supply that the US could use up our reserves within several decades.

• Problems: Disposal of nuclear waste, limited supply of U-235 and reactor meltdowns

ConservationConservation

• Conservation is the use of natural resources in a way that ensures their continuing availability to future generations.

• USE ENERGY EFFICIENTLY– Turn off unused lights and appliances– Use fluorescent or halogen bulbs– Buy fuel efficient cars

• REMEMEBER, THESE RESOURCES ARE FINITE ON A HUMAN TIMESCALE!

US Energy ProductionUS Energy Production

US Energy ConsumptionUS Energy Consumption

Key TermsKey Terms• Fuels Substances that provide energy

as the result of a chemical change.• Combustion The process of burning a

fuel to change chemical energy into thermal energy.

• Fusion The combining of 2 atomic nuclei to produce one large nuclei and energy. It produces more energy than nuclear fission.

• Nucleus The central part of an atom.

Chapter 17 Chapter 17

Alternative Energy SourcesAlternative Energy Sources

Renewal ResourcesRenewal Resources

• Renewable resources: are those resources which are replaceable on a human life timescale.

• Are responsible for just 8% of the total energy consumed in the US in 2002.

Examples:-Hydropower-Wind Energy-Solar Energy-Geothermal Energy

HydropowerHydropower• Hydropower is the energy generated due to falling

or flowing water through turbines.• Use: Hydroelectric power is the most widely used

nonrenewable resource and has consistently supplied a small percentage of US energy needs for several decades; it currently provides about 3% of US energy.

• Limitations: – We have already harvested most of our feasible water

energy. – Sediment buildup and ecosystem disruption cause

problems.

HydropowerHydropower

Wind EnergyWind Energy

• Wind energy is produced from turbines in windmills Aerogenerators

• Is actually an indirect form of solar energy.

• Uses: Generating electricity, and pump ground water

• Limitations: Can only be produced in windy areas, higher cost, wind can be erratic

Wind EnergyWind Energy

Gamesa wind turbine installed at Bald Mountain in Bear Creek Township, PA

Solar EnergySolar Energy

• Energy captured from the sun by photovoltaic cells or solar cells.

• Uses: generate electricity, especially in remote regions of the earth and for satellites.

• Advantage: This source will last for at least a billion years.

• Limitations: very expensive to produce, uses vast areas of land to harvest, not a consistent source of energy

Solar EnergySolar Energy

Passive solar heating – The sun’s energy is collected, stored and distributed naturally in an enclosed dwelling.

ex. Greenhouse, windows

Active solar heating – Devices are used to collect, store, and circulate heat produced from solar energy. Ex. Solar collectors, Photovoltaic cells Use thin wafers of semiconductor material to produce electricity.

Solar EnergySolar Energy

Geothermal EnergyGeothermal Energy

• Heat from cooling magma heats ground water near the earth’s surface.

• Geothermal energy is harvested by capturing the energy out of this heated water.

• Large amounts of energy can only be generated in geologically active zones.

• Uses: to heat/cool houses and household water supplies, very few utility plants

(Montgomery, 2006).• Limitation: Ground cools eventually

Geothermal EnergyGeothermal Energy

Nuclear FusionNuclear Fusion

• Nuclear fusion occurs when two atomic nuclei fuse to become one larger nucleus.

• Occurs in the sun.• Fuel used is usually deuterium or H-2.

– Must be subjected to extremely high temperatures and pressures supplied by either magnetic field or lasers.

• Advantages: Much less radioactive waste• Disadvantage: Very hard to do.

E = mcE = mc²²

• Two protons stuck together have less mass than two single separate protons!

• When the protons are forced together, this extra mass is released ... as energy!

• Typically this amounts to about 7% of the total mass, converted to an amount of energy predictable using the formula.

• C = speed of light (3 x 108) m/s

Alternative Energy Sources for the Alternative Energy Sources for the FutureFuture

• Nuclear Fusion

• Tidal Power

• Ocean Thermal Energy Conversion

• Rebirth of Wood Burners

• Alcohol and Ethanol

• Biogas

World Energy Production By World Energy Production By SourceSource

Key TermsKey Terms

• Non-renewable resource

• Fossil Fuel• Coal• Oil• Natural Gas• Conservation

• Nuclear Energy• Renewable resource• Wind energy• Geothermal energy• Solar Energy• Hydropower

ClosureClosure

• We know there is a limited amount of non-renewable resources on earth.

• As technology improves, we may be better able to harness renewable resources and find new sources of energy.

• It is still our responsibility to conserve the resources we have today for future generations and to help preserve the earth.

• Please list five things you can do to conserve energy.

ReferencesReferences

Appenzeller, Tim. (2004, June). The end of cheap oil. National Geographic, 205(6), 88-89.

Montgomery, Carla W. (2006). Environmental Geology (7th ed.). New York: McGraw-Hill.