“Typical citizens of advanced industrialized nations each consume as much energy in 6 months as typical citizens in less developed countries consume during their entire life.” Maurice Strong

Nonrenewable Energy Resources Unit 11

FYI: Laws of Thermodynamics 1 st Law: energy cannot be created nor destroyed 2 nd Law: high-quality energy is degraded to low- quality energy

Net Energy Net energy: total amount of useful energy available from a resource minus energy needed to make it available to consumers -ratio: energy produced to energy used to produce it

Net Energy Ratios the higher the net energy ratio, the greater the net energy available ratios < 1 indicate a net energy loss EROEI: Energy Return On Energy Investment EROEI= energy from fuel or Energy Out energy invested in fuel Energy In

Fig. 16-4, p. 358 Space Heating Passive solar 5.8 Natural gas Oil 4.5 Active solar 1.9 Coal gasification 1.5 Electric resistance heating (coal-fired plant) 0.4 Electric resistance heating (nuclear plant) 0.3 High-Temperature Industrial Heat 28.2 Surface-mined coal Underground-mined coal 25.8 Natural gas 4.9 Oil 4.7 Coal gasification 1.5 Direct solar (highly concentrated by mirrors, heliostats, or other devices) 0.9 Transportation Natural gas 4.9 Gasoline (refined crude oil) 4.1 Biofuel (ethyl alcohol) 1.9 Coal liquefaction 1.4 Oil shale 1.2 Electric resistance heating (natural-gas-fired plant) 4.9

Fossil Fuels Fossil fuels: solid, liquid, gaseous forms of ancient vegetation, animal matter buried inside the earth’s crust Coal Oil/petroleum Natural gas

Coal Most abundant fossil fuel Produces most of world’s electricity Formation begins with peat: decomposed plant debris buried for millions of years Stages of coal (from youngest to oldest): -peat: lowest energy content -lignite -sub-bituminous coal -bituminous coal -anthracite coal: highest energy content

Fig , p. 368 Increasing heat and carbon content Increasing moisture content Peat (not a coal) Lignite (brown coal) Bituminous (soft coal) Anthracite (hard coal) Heat Pressure Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas

Coal Coal reserves in the United States, Russia, and China could last hundreds to over a thousand years. – the U.S. has 27% of the world’s proven coal reserves, followed by Russia (17%), and China (13%). – in 2005, China and the U.S. accounted for 53% of the global coal consumption.

Define the Following

Coal Coal can be converted into synthetic natural gas -SNG or syngas- and liquid fuels- methanol or synthetic gasoline- that burn cleaner than coal. -conversion costs are high -adds more CO 2 to the troposphere than burning coal (U.S. coal-burning plants aren’t likely to invest in coal gasification due to cost)

Coal Use Trade-Offs AdvantagesDisadvantages Ample supplies (225–900 years) Severe land disturbance, air and water pollution High net energy yieldHigh land use Low cost (with huge subsidies) Releases mercury into environment Air pollution can be reduced with improved technology (but adds to cost) Severe threat to human health

Crude Oil/Petroleum Formed from remains of ancient phytoplankton Mixture of liquids, gases, solids -liquid form: fuel oil, gasoline for heating, transportation -gaseous form: propane, butane for heat, cooking -solid form: grease, wax, petroleum jelly, asphalt

Refining Crude Oil Oil refinery: separates, purifies crude oil at layers in a distillation column Fractional distillation: different boiling points separate parts of crude oil -most volatile components with lowest boiling points are removed at the top Petrochemicals: products of distillation used in plastics, pesticides, paints, clothing fibers

Fig. 16-5, p. 359 Gases Gasoline Aviation fuel Heating oil Diesel oil Naptha Grease and wax Asphalt Heated crude oil Furnace

Global Oil Supplies Global peak production: maximum rate of oil production (after which prices rise) -oil is single largest source of energy -expected to increase by 37% by 2030 Largest oil producers: Saudi Arabia, Russia, US, Iran, China, Canada, Mexico Largest oil consumers: US (23%), China(8%), Japan (6%)

Proven Reserves OPEC: Organization of Petroleum Exporting Countries have 78% of world’s oil proven reserves (and most of the world’s unproven reserves) -include Iran, Iraq, Saudi Arabia, Kuwait, Venezuela, Russia -rising oil prices threaten global economies that have not shifted to new energy alternatives

Hubbert Curve: Projects Peak Oil Production

Case Study: U.S. Oil Supplies U.S. has only 2.9% of the world’s proven oil reserves 60% of U.S oil imports goes through refineries in hurricane-prone regions of Gulf Coast May result in drilling environmentally sensitive areas ex. Arctic National Wildlife Refuge(ANWR)

Oil Use Trade Offs AdvantagesDisadvantages Ample supply for decadesWater pollution from spills, leaks High net energy yield (but decreasing) Environmental costs not included in market price Low land disruptionReleases CO₂ when burned Efficient distribution system Vulnerable to international supply interruptions

Oil Spills 1989 Exxon Valdez, Prince William Sound, Alaska: 11 million gallons of oil 2010 BP Deepwater Horizon, Gulf of Mexico, 11 workers killed: 206 million gallons of oil

Natural Gas Formed, found alongside crude oil, coal 90% methane (CH₄), propane, ethane, butane High net energy yield Produces less CO₂ than coal, oil Can be converted to liquified natural gas (LNG) at high temp. for transport in pipelines -requires energy to compress, transport gas

Global Gas Supplies Russia has ≈25% of gas reserves, followed by Iran, Qatar US has ≈3% of gas reserves, but uses 22% of global reserves

Gas Trade-Offs AdvantagesDisadvantages Ample supplyDifficult, costly to transport long distances High net energy yieldLow energy yield for LNG Emits fewer greenhouse gases than other fossil fuels Releases greenhouse gases

Hydraulic Fracturing: “Fracking” Extraction of gas by “thumper” trucks Fractures host rock with water, sand, chemicals Contaminated water is injected back into ground Evidence links fracking with earthquakes

Oil Shale, Tar Sands Oil/tar sands: mixture of clay, sand, oily bitumen Oil shale: oily rocks -potentially large supply, especially in Canada -easily transported -low net energy yield (requires natural gas) -releases greenhouse gases, air pollutants, high land use (strip-mined), high water use, toxic sludge

Synfuels Liquids, gases produced from coal by liquefaction, gasification -large quantity of energy -produce low net energy yield

Synfuel Trade-Offs AdvantagesDisadvantages Ample supplyLow to moderate net energy yield Can be used as vehicle fuelRequires mining 50% more coal so increased land disruption, increased pollution Lower air pollution than coal Higher CO₂ emissions than coal

Nonrenewable Energy Unit 11: Part 2

FYI: Nuclear Fission Review Isotope: element with the same atomic # (protons), but different # of neutrons ex. U-238 and U-235 (both have 92 protons) Fission: process of splitting a large atom into two smaller atoms of different elements, releasing neutrons Fission reaction: neutron of one atom collides with and splits another, creating a chain reaction of energy release.

Nuclear Energy Converts nuclear bonds into thermal energy Goal: produce electricity Task: use nuclear fission to boil water, produce steam, spin turbine, generate electricity (same goal as fossil fuels, wind, etc) Fuel used: Uranium-235 -mined from ore with U-238 -must be enriched from 1% to 3% U-235 -pelletized (each has the energy equivalent of 1 ton of coal)

Nuclear Reactor Site of “controlled” fission reaction Most common type: light-water reactors (LWR) -produce 85% of global nuclear energy (100% in US) -France, Japan are biggest producers of nuclear power

Nuclear Reactor (cont’d) Fuel rods: packed with U pellets; placed in reactor core Control rods: contain neutron-absorbing material (graphite) to control amount of heat from fission reaction; moved between fuel rods

Nuclear Reactor (cont’d) Moderator: slows down neutrons to trigger chain reactions (near pure water) Containment shell: steel-reinforced concrete shell around the reactor core Coolant: usually water, circulates in 3 loops around core for backup cooling to prevent meltdown

Fig , p. 372 Small amounts of radioactive gases Uranium fuel input (reactor core) Control rods Containment shell Heat exchanger Steam Turbine Generator Waste heat Electric power Hot coolant Useful energy 25%–30% Hot water output Pump Coolant Pump Moderator Cool water input Waste heat Shielding Pressure vessel Coolant passage Water Condenser Periodic removal and storage of radioactive wastes and spent fuel assemblies Periodic removal and storage of radioactive liquid wastes Water source (river, lake, ocean)

Fig , p. 376 Coal vs. Nuclear Trade-Offs CoalNuclear Ample supply Ample supply of uranium High net energy yield Low net energy yield Very high air pollution Low air pollution (mostly from fuel reprocessing) High CO 2 emissions Low CO 2 emissions (mostly from fuel reprocessing) High land disruption from surface mining Much lower land disruption from surface mining Low cost (with huge subsidies) High cost (even with huge subsidies) High land use Moderate land use

Costs of Nuclear Energy Nuclear power is globe’s slowest-growing form of energy due to: Dependence on huge government subsidies; multi-billion-dollar construction High operation costs -every 3-4 yrs fuel, fuel rods must be replaced Corrosion, embrittlement of equipment shortens reactor life from yrs

Hazards of Nuclear Energy No long term safe storage of spent equipment (wastes must be stored for a min. of 10,000 yrs) Currently stored in water-filled pools, dry casks. Other options: deep burial (in 60 years, no country has figured out how to do this) shoot into space bury in Antarctic ice sheet

Nuclear Waste Containment (After spent fuel rods are cooled considerably, they are sometimes moved to dry-storage containers made of steel or concrete) Figure 16-17

Fig , p. 373 Decommissioning of reactor Fuel assemblies Reactor Enrichment of UF 6 Fuel fabrication (conversion of enriched UF 6 to UO 2 and fabrication of fuel assemblies) Temporary storage of spent fuel assemblies underwater or in dry casks Conversion of U 3 O 8 to UF 6 Uranium-235 as UF 6 Plutonium-239 as PuO 2 Spent fuel reprocessing Low-level radiation with long half-life Geologic disposal of moderate & high- level radioactive wastes Open fuel cycle today “Closed” end fuel cycle

Hazards of Nuclear Energy (cont’d) Leaking radioactivity is harmful to life Thermal pollution from released coolant

Political Concerns Materials could be used for nuclear weapons Nuclear accidents could spread radiation across countries Terrorist attacks Not profitable

Case Study: Three Mile Island 1979: nuclear meltdown in Pennsylvania nuclear power plant was narrowly avoided

Case Study: The Chernobyl Nuclear Power Plant Accident 1986: world’s worst nuclear power plant accident occurred in Ukraine. The disaster was caused by poor reactor design and human error. By 2005, 56 people had died from radiation released. – 4,000 more are expected from thyroid cancer and leukemia.

Case Study: Yucca Mountain 1987: first proposed high-level radioactive waste repository in world -100 mi. north of Las Vegas -$10.4 billion spent on research ($2 billion spent by power company) 2009: site was scrapped due to instability of rock formations in area

New and Safer Reactors Pebble bed modular reactor (PBMR) are smaller reactors that minimize the chances of runaway chain reactions. Figure 16-21

Nuclear Fusion Energy Nuclear fusion is a nuclear change in which two isotopes are forced together. - No risk of meltdown or radioactive releases -May also be used to breakdown toxic material -Still in laboratory stages.

Exam Focus: Part One Definition of “net energy” Types of fossil fuels- advantages and disadvantages of all three -which releases mercury Stages of coal (pay attention to water, sulfur content) Types of natural gas How fossil fuels are related to solar energy OPEC (countries)