2 Section 15.1 the need for energy Forms of energyMechanical energy – motion- Also known as Kinetic energy.Chemical energy – stored energy (food)- Also known as Potential energy.Nuclear energy – nucleus of an atomThermal energy - heatLaw of conservation of energy– states that energy cannot be created or destroyed but it can change forms.
3 Law of conservation of energy ThermalChemicalMechanicalChemicalFood is a form of fuel that your body uses for energy.Fuel – any substance from which energy can be obtained.Fossil Fuels – fuels derived from the remains of organisms that lived long agoThey contain a great deal of energy.Also known as an organic fuel.
4 Section 15.2 coalFormed from plant remains that were once living in swamps.The plant matter loses hydrogen and oxygen, leaving behind carbon.Takes over millions of years to form; nonrenewable.4 stages1. Peat - brittle, brown plant material (resembles decaying wood)Contains a lot of water and a low percentage of carbon.Gives off a lot of smoke because high in water.Not a form of coal.
5 Section 15.2 coal2. Lignite – soft, brown coal; composed of 40% carbonHeat and pressure forces the water out of peat, forming lignite.Burns quickly and gives off very little smoke.Located below earth’s surface and must be mined.First true form of coal!3. Bituminous Coal - soft coal; composed of up to 85% carbonForms deep in the earth’s crust.Most abundant type mined in the U.S.Burns hotter and with less smoke than peat or ligniteUsed in many power plants to produce the energy needed to heat water into steam that generates electricity.
6 Section 15.2 coal4. Anthracite Coal - a hard coal; composed of up to 95% carbonMetamorphic rock, shiny, black colorLeast water, fewest impurities, and highest carbon contentBurns the hottest with the least amount of smoke (clean)Least abundant therefore the most expensive form of coal.Most often used to heat homes.
7 Geology Link Diamonds are also formed from carbon Coal is formed from plant remains; diamonds are formed from extreme heat and pressure in Earth’s mantleMany diamond mines are located in South AfricaHardest mineralUsed for cutting and drilling as well as for jewelry
8 Section 15.3 Petroleum & natural gas Also called crude oil.Liquid fossil fuel thought to be formed from remains of plankton and microscopic protists, plants, and animals living millions of years ago.Over millions of years, the heat and pressure from the ocean floor converted the remains into a syrupy liquid called petroleum.Pressure from overlying rocks forced the petroleum to moved upward through pores of sedimentary rocks. When the petroleum met nonporous rock, it became trapped below the surface.
10 Petroleum continued…… A great deal of pressure can build up in an oil pool trapped below the groundWhen a well is drilled into this pool, the pressure forces the oil to shoot upward, forming a gusherIf there is little or no pressure, oil must be pumped to the surfaceGas and jet fuels, diesel fuel, fuel oil, grease, lubricants, plastics, asphalt, nylon, & polyester come from petroleumOne of the world’s most important resourcesNonrenewable
11 Section 15.3 Petroleum & natural gas Mixture of mostly gaseous hydrocarbonsMethane, ethane, propane are some types.Forms like petroleumFound trapped above petroleum poolsViewed as a waste or by-product of petroleum drillingWidely used in industryBurns cleaner than other fuelsUsed in stoves, water heaters, and clothes dryersMore energy efficient because it does not have to be converted to electricity to be used.
13 Section 15.4 Other organic Fuels Problems with fossil fuelsAvailabilityNonrenewableNot located everywherePollutionOil spillsAir pollutionCO2 released into air (greenhouse effect)DangerousNatural gas is extremely combustible; coal miners can die of suffocation by natural gasEnvironmental damage
14 Section 15.4 Other organic Fuels Biomass FuelsA fuel formed from the products of living organismsRenewable!Examples include: wood, garbage, methane, and alcohol1. WoodIn developing nations where fuels are too expensive, people rely on wood for fuel.Disadvantages – Gives off a lot of smoke high in CO2; damages forests.
15 Biomass Fuels continued…… 2. GarbageComposed largely of organic material (paper, food scraps)2/3 of material in garbage cans be burned.Some U.S. cities are burning garbage to produce electricity.Using it as a biomass fuel would help solve the problem of running out of land fill space.3. MethaneSwamp gas from decaying plantsDecaying garbage in dumps produces methane.Used the same way as natural gas.
16 Biomass fuels continued…… 4. AlcoholBioconversion – the conversion of organic materials into fuelsSugarcane and corn (plants) can make alcohol through bioconversion.Alcohol is a hydrocarbon in which one of the hydrogen atoms has been replaced with hydroxyl (OH)
17 Biomass fuels continued…… This ethanol is made by yeast through a process called fermentationEthanol is a liquid biomass that burns cleanly and is a renewable resource.In Brazil, >2million cars are fueled by ethanolOther cars are fueled by gasohol (90% gasoline + 10% ethanol)Manufacturers are also producing cars that run on alcohol made from sunflower or peanut plants