Presentation on theme: "Nonrenewable Energy Resources Chapter 17"— Presentation transcript:
1Nonrenewable Energy Resources Chapter 17 Advanced Placement Environmental Science
21. Energy Resources2. Oil3. Natural Gas4. Coal5. Nuclear Energy
3Energy SourcesModern society requires large quantities of energy that are generated from the earth’s natural resources.Primary Energy Resources: The fossil fuels(oil, gas, and coal), nuclear energy, falling water, geothermal, and solar energy.Secondary Energy Resources: Those sources which are derived from primary resources such as electricity, fuels from coal, (synthetic natural gas and synthetic gasoline), as well as alcohol fuels.
4ThermodynamicsThe laws of thermodynamics tell us two things about converting heat energy from steam to work:1) The conversion of heat to work cannot be 100 % efficient because a portion of the heat is wasted.2) The efficiency of converting heat to work increases as the heat temperature increases.
5Energy Units and UseBTU (British Thermal Unit) - amount of energy required to raise the temperature of 1 lb. of water by 1 ºF.cal (calorie) - the amount of energy required to raise the temperature of 1 g of water by 1 ºC. Commonly, kilocalorie (kcal) is used.1 Btu = 252 cal = kcal1 Btu = 1055 J (joule) = kJ1 cal = J
6Energy Units and UseTwo other units that are often seen are the horsepower and the watt. These are not units of energy, but are units of power.1 watt (W) = BTU/hour1 horsepower (hp) = 746 WWatt-hour - Another unit of energy used only to describe electrical energy. Usually we use kilowatt-hour (kW-h) since it is larger.quad (Q) - used for describing very large quantities of energy. 1 Q = 1015 Btu
7Evaluating Energy Resources U.S. has 4.6% of world population and uses 24% of the world’s energy.84% from nonrenewable fossil fuels (oil, coal, & natural gas).7% from nuclear power.9% from renewable sources (hydropower, geothermal, solar, biomass).
9Energy resources removed from the Earth’s crust include: oil, natural gas, coal, and uranium.
10Fossil FuelsFossil fuels originated from the decay of living organisms millions of years ago, and account for about 80% of the energy generated in the U.S.The fossil fuels used in energy generation are:Natural gas, which is % methane (CH4)Liquid hydrocarbons obtained from the distillation of petroleumCoal - a solid mixture of large molecules with a H/C ratio of about 1
11Problems with Fossil Fuels Fossil fuels are nonrenewable resources.At projected consumption rates, natural gas and petroleum will be depleted before the end of the 21st century.Impurities in fossil fuels are a major source of pollution.Burning fossil fuels produce large amounts of CO2, which contributes to global warming.
122. Oil 1. Energy Resources 3. Natural Gas 4. Coal 5. Nuclear Energy
13OilDeposits of crude oil often are trapped within the earth's crust and can be extracted by drilling a well.Fossil fuel, produced by the decomposition of deeply buried organic matter from plants and animals.Crude oil: complex liquid mixture of hydrocarbons, with small amounts of S, O, N impurities.How Oil Drilling Works by Craig C. Freudenrich, Ph.D. – read the entire article on science.howstuffworks.com.
14Sources of OilOrganization of Petroleum Exporting Countries (OPEC) – 13 countries have 67% world reserves:Algeria, Ecuador, Gabon, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, & VenezuelaOther important producers:Alaska, Siberia, & Mexico.
26Sources of Natural GasRussia & Kazakhstan - almost 40% of world's supply.Iran (15%), Qatar (5%), Saudi Arabia (4%), Algeria (4%), United States (3%), Nigeria (3%), Venezuela (3%).90–95% of natural gas in U.S. domestic (~411,000 km = 255,000 miles of pipeline).
31Natural GasWhen a natural gas field is tapped, propane and butane are liquefied and removed as liquefied petroleum gas (LPG).The rest of the gas (mostly methane) is dried, cleaned, and pumped into pressurized pipelines for distribution.Liquefied natural gas (LNG) can be shipped in refrigerated tanker ships.
334. Coal 1. Energy Resources 2. Oil 3. Natural Gas 5. Nuclear Energy
34Coal: Supply and Demand Coal exists in many forms therefore a chemical formula cannot be written for it.Coalification: After plants died they underwent chemical decay to form a product known as peat.Over many years, thick peat layers formed.Peat is converted to coal by geological events such as land subsidence which subject the peat to great pressures and temperatures.
37Ranks of CoalAnthracite : A hard, black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Energy content of about 14,000 Btu/lb.Bituminous: Most common coal and is dense and black (often with well-defined bands of bright and dull material). Its moisture content usually is less than 20 percent. Energy content about 10,500 Btu / lb.Subbituminous: Black lignite and is dull black and generally contains 20 to 30 percent moisture Energy content is 8,300 BTU/lb.Lignite: A brownish-black coal of low quality (i.e., low heat content per unit) with high inherent moisture and volatile matter. Energy content is lower than 4,000 BTU/lb.
43Sulfur in CoalWhen coal is burned, sulfur is released primarily as sulfur dioxide (SO2 - serious pollutant).Coal Cleaning - Methods of removing sulfur from coal include cleaning, solvent refining, gasification, and liquefaction. Scrubbers are used to trap SO2 when coal is burned.Two chief forms of sulfur are inorganic (FeS2 or CaSO4) and organic (Sulfur bound to Carbon).
50RadioactivityRadioactive decay continues until the the original isotope is changed into a stable isotope that is not radioactive.Radioactivity: Nuclear changes in which unstable (radioactive) isotopes emit particles & energy.
51Radioactivity Types Sources of natural radiation Alpha particles consist of 2 protons and 2 neutrons, and therefore are positively chargedBeta particles are negatively charged (electrons)Gamma rays have no mass or charge, but are a form of electromagnetic radiation (similar to X-rays)Sources of natural radiationSoilRocksAirWaterCosmic rays
53Half-LifeThe time needed for one-half of the nuclei in a radioisotope to decay and emit their radiation to form a different isotope.Half-time emittedUranium million yrs alpha, gammaPlutonium yrs alpha, gammaDuring operation, nuclear power plants produce radioactive wastes, including some that remain dangerous for tens of thousands of years.
55Effects of Radiation Genetic Damages: from mutations that alter genes. Genetic defects can become apparent in the next generation.Somatic Damages: to tissue, such as burns, miscarriages, and cancers.
57Radioactive Waste Low-level radiation (Gives off low amount of Sources: nuclear power plants, hospitals, and universities.most was dumped into the ocean.Today deposited into landfills.High-level radiation (Gives off large amount ofFuel rods from nuclear power plants.Half-time of Plutonium 239 is 24,000 years.No agreement about a safe method of storage.
58Radioactive Waste 1. Bury it deep underground. Problems: i.e., earthquake, groundwater…2. Shoot it into space or into the sun.Problems: costs, accident would affect large area.3. Bury it under the Antarctic ice sheet.Problems: long-term stability of ice is not known, global warming.4. Most likely plan for the US.Bury it into Yucca Mountain in desert of Nevada.Cost of over $ 50 billion.160 miles from Las Vegas.Transportation across the country via train & truck.
60Plutonium Breeding 238U is the most plentiful isotope of Uranium. Non-fissionable - useless as fuel.Reactors can be designed to convert 238U into a fissionable isotope of plutonium, 239Pu.
61Conversion of 238U to 239PuUnder appropriate operating conditions, the neutrons given off by fission reactions can "breed" more fuel, from otherwise non-fissionable isotopes, than they consume.Source:EVR3019/Nuclear_Waste.ppt
62Reprocess Nuclear Fuel During the operation of a nuclear reactor the uranium runs out.Accumulating fission products hinder the proper function of a nuclear reactor.Fuel needs to be (partly) renewed every year.Source:
63Plutonium in Spent Fuel Spent nuclear fuel contains many newly formed plutonium atoms.Miss out on the opportunity to split.Plutonium in nuclear waste can be separated from fission products and uranium.Cleaned Plutonium can be used in a different Nuclear Reactor.Source:
65Nuclear EnergyConcerns about the safety, cost, and liability have slowed the growth of the nuclear power industry.Accidents at Chernobyl and Three Mile Island showed that a partial or complete meltdown is possible.
67Three Mile IslandMarch 29, 1979, a reactor near Harrisburg, PA, lost coolant water because of mechanical and human errors and suffered a partial meltdown.50,000 people evacuated & another 50,000 fled area.Unknown amounts of radioactive materials released.Partial cleanup & damages cost $1.2 billion.Released radiation increased cancer rates.
69ChernobylApril 26, 1986, reactor explosion (Ukraine) flung radioactive debris into atmosphere.Health ministry reported 3,576 deaths.Green Peace estimates32,000 deaths.About 400,000 people were forced to leave their homes.~160,000 sq km (62,00 sq mi) contaminated.> Half million people exposed to dangerous levels of radioactivity.Cost of incident > $358 billion.
72Nuclear EnergyNuclear plants must be decommissioned after years.New reactor designs are still proposed.Experimental breeder nuclear fission reactors have proven too costly to build and operate.Attempts to produce electricity by nuclear fusion have been unsuccessful.
73Use of Nuclear Energy U.S. phasing out. Some countries (France, Japan) investing is increasing.U.S. currently ~7% of energy is nuclear.No new U.S. power plants ordered since 1978.40% of 105 commercial nuclear power plants expected to be retired by 2015 and all by 2030.North Korea is getting new plants from the US.France has 78% of energy from nuclear.
74Phasing Out Nuclear Power Multi-billion-$$ construction costsHigh operation costsFrequent malfunctionsFalse assurances and cover–upsOverproduction of energy in some areasPoor managementLack of public acceptance