Nonrenewable Energy

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Chapter 16

• Nonrenewable Energy

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Chapter Overview Questions

• What are the advantages and disadvantages of
  conventional oil and nonconventional heavy oils?
• What are the advantages and disadvantages of
  natural gas?
• What are the advantages and disadvantages of coal
  and the conversion of coal to gaseous and liquid
  fuels?

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Chapter Overview Questions (contd)

• What are the advantages and disadvantages of
  conventional nuclear fission, breeder nuclear
  fission, and nuclear fusion?

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Core Case Study How Long Will the Oil Party
Last?

• Saudi Arabia - 10 year oil supply
• Alaskas North Slope - 6 months (U.S. 3 years).
• Alaskas Arctic National Wildlife Refuge (ANWR) -
  1-5 months (U.S. 7-25 months).

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Core Case Study How Long Will the Oil Party
Last?

• Three options
• Look for more
• Use or waste less
• Use something else.

Figure 16-1
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TYPES OF ENERGY RESOURCES

• 99 of the energy warms us comes from the sun and
  the other 1 comes mostly from burning fossil
  fuels.
• Solar energy indirectly supports wind power,
  hydropower, and biomass.
• 76 of commercial energy comes from nonrenewable
  fossil fuels (oil, natural gas, and coal)
• The remainder comes from renewable

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TYPES OF ENERGY RESOURCES

• Nonrenewable energy resources and geothermal
  energy in the earths crust.

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TYPES OF ENERGY RESOURCES

• Commercial energy use by source for the world and
  the U.S.

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Animation Energy Use
PLAY ANIMATION
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TYPES OF ENERGY RESOURCES

• Net energy the amount of high-quality usable
  energy available from a resource (minus) the
  energy needed to make it available

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Net Energy Ratios

• The higher the net energy ratio, the greater the
  net energy available.
• Ratios lt 1 indicate a net energy loss.

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OIL

• Crude oil (petroleum)
• thick liquid containing hydrocarbons
• extracted from underground deposits
• separated through FRACTIONAL DISTILLATION
• Only 35-50 can be economically recovered from a
  deposit.
• About 10-25 more can be recovered from expensive
  secondary extraction techniques.
• This lowers the net energy yield.
• Only done when prices rise

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OIL

• Refining crude oil
• Based on boiling points
• The most volatile components with the lowest
  boiling points are removed at the top.
• Fractional Distillation

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OIL

• Eleven OPEC (Organization of Petroleum Exporting
  Countries) have 78 of the worlds proven oil
  reserves and most of the worlds unproven
  reserves.
• After global production peaks and begins to
  decline, oil prices will rise and could threaten
  the economies of countries that have not shifted
  to new energy alternatives.

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OIL

• Inflation-adjusted price of oil, 1950-2006.

Figure 16-6
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Case Study U.S. Oil Supplies

• U.S. worlds largest oil user has only 2.9
  of the worlds proven oil reserves.
• U.S oil production peaked in 1974 (halfway
  production point).
• About 60 of U.S oil imports goes through
  refineries in hurricane-prone regions of the Gulf
  Coast.

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OIL

• Burning oil for transportation accounts for 43
  of global CO2 emissions.

Figure 16-7
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CO2 Emissions

• CO2 emissions per unit of energy produced for
  various energy resources.

Figure 16-8
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Heavy Oils from Oil Sand and Oil Shale Will
Sticky Black Gold Save Us?

• Oil sand and oil shale could supplement
  conventional oil
• Environmental problems.
• High sulfur content.
• Extracting and processing
• Toxic sludge
• Uses and contaminates larges volumes of water
• Requires large inputs of natural gas (reduces net
  energy yield)

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Oil Shales

• Oil shales contain a solid combustible mixture of
  hydrocarbons called kerogen.

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Heavy Oils

• It takes about 1.8 metric tons of oil sand to
  produce one barrel of oil.

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NATURAL GAS

• Natural gas (mostly methane), is often found
  above reservoirs of crude oil.
• When a natural gas-field is tapped, gasses are
  liquefied and removed as liquefied petroleum gas
  (LPG).
• Coal beds and bubbles of methane trapped in ice
  crystals deep under the arctic permafrost and
  beneath deep-ocean sediments are unconventional
  sources of natural gas.

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NATURAL GAS

• Russia and Iran
• Almost half of the worlds reserves of
  conventional gas
• Global reserves should last 62-125 years.
• Natural gas
• Versatile and clean-burning fuel
• Releases the carbon dioxide (when burned) and
  methane (from leaks) into the troposphere.

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NATURAL GAS

• Best fuel to help make the transition to improved
  energy efficiency and greater use of renewable
  energy.

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COAL

• Solid fossil fuel
• Formed in several stages
• Buried remains of land plants (300-400mya)

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The largest coal-burning power plant in the
United States in Indiana burns 23 metric tons (25
tons) of coal per minute or three 100-car
trainloads of coal per day and produces 50 more
electric power than the Hoover Dam.
Waste heat
Cooling tower transfers waste heat to atmosphere
Coal bunker
Turbine
Generator
Cooling loop
Stack
Pulverizing mill
Condenser
Filter
Boiler
Toxic ash disposal
Fig. 16-13, p. 369
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COAL

• Coal reserves in the US, Russia, and China
• Hundreds to over a thousand years
• Proven coal reserves
• U.S. (27)
• Russia (17)
• China (13)
• 2005, China U.S. 53 global coal consumption

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COAL

• Most abundant fossil fuel
• Compared to oil and natural gas it is not as
  versatile
• High environmental impact
• Releases much more CO2 into the troposphere.

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How Would You Vote?

• Should coal use be phased out over the next 20
  years?
• a. No. Coal is an abundant energy source and we
  should continue to develop clean ways to use it.
• b. Yes. Mining and combusting coal create serious
  environmental impacts.

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COAL

• Can be converted into synthetic natural gas (SNG
  or syngas) and liquid fuels (methanol or
  synthetic gasoline) that burn cleaner than coal.
• Costs are high.
• They add more CO2 to the troposphere than burning
  coal.

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COAL

• Since CO2 is not regulated as an air pollutant
  and costs are high, U.S. coal-burning plants are
  unlikely to invest in coal gasification.

Figure 16-15
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NUCLEAR ENERGY

• Isotopes of uranium and plutonium undergo
  controlled nuclear fission
• Resulting heat produces steam that spins turbines
  to generate electricity.
• The uranium oxide consists of about 97
  nonfissionable uranium-238 and 3 fissionable
  uranium-235.
• The concentration of uranium-235 is increased
  through an enrichment process.

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Small amounts of radioactive gases
Uranium fuel input (reactor core)
Control rods
Containment shell
Heat exchanger
Turbine
Steam
Generator
Electric power
Waste heat
Hot coolant
Useful energy 2530
Hot water output
Pump
Pump
Coolant
Pump
Pump
Waste heat
Cool water input
Moderator
Coolant passage
Pressure vessel
Shielding
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. 16-16, p. 372
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NUCLEAR ENERGY

• After three or four years in a reactor, spent
  fuel rods are removed and stored in a deep pool
  of water contained in a steel-lined concrete
  container.

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NUCLEAR ENERGY

• After spent fuel rods are cooled, they are
  sometimes moved to dry-storage containers made of
  steel or concrete.

Figure 16-17
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Decommissioning of reactor
Fuel assemblies
Reactor
Enrichment of UF6
Fuel fabrication
(conversion of enriched UF6 to UO2 and
fabrication of fuel assemblies)
Temporary storage of spent fuel assemblies
underwater or in dry casks
Conversion of U3O8 to UF6
Uranium-235 as UF6 Plutonium-239 as PuO2
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
Fig. 16-18, p. 373
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What Happened to Nuclear Power?

• More than 50 years of development
• Enormous government subsidies
• Still not lived up to its promise
• Multi billion-dollar construction costs.
• Higher operation costs and more malfunctions than
  expected.
• Poor management.
• Public concerns about safety and stricter
  government safety regulations.

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Chernobyl Nuclear Power Plant Accident

• Worlds worst nuclear power plant accident
  occurred in 1986 in Ukraine.
• 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.

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Animation Chernobyl Fallout
PLAY ANIMATION
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NUCLEAR ENERGY

• World Bank (95) said nuclear power is too costly
  and risky.
• In 2006, it was found that several U.S. reactors
  were leaking radioactive tritium into groundwater.

Figure 16-19
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NUCLEAR ENERGY

• A 1,000 megawatt nuclear plant is refueled once a
  year, whereas a coal plant requires 80 rail cars
  a day.

Figure 16-20
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NUCLEAR ENERGY

• Terrorists
• could attack nuclear power plants (especially
  poorly protected pools and casks that store spent
  nuclear fuel rods.)
• could wrap explosives around small amounts of
  radioactive materials that are fairly easy to
  get, detonate such bombs, and contaminate large
  areas for decades.

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NUCLEAR ENERGY

• Decommissioning
• When a nuclear reactor reaches the end of its
  useful life
• highly radioactive materials must be kept from
  reaching the environment for thousands of years.
• At least 228 large commercial reactors worldwide
  (20 in the U.S.) are scheduled for retirement by
  2012.
• Many applying to extend 40-yr license to 60 yrs
• Aging reactors - embrittlement and corrosion.

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NUCLEAR ENERGY

• Does not lessen dependence on imported oil
• Will not reduce CO2 emissions as much as others
• The nuclear fuel cycle contributes to CO2
  emissions.
• Wind turbines, solar cells, geothermal energy,
  and hydrogen contributes much less to CO2
  emissions.

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NUCLEAR ENERGY

• Scientists disagree about the best methods for
  long-term storage of high-level radioactive
  waste
• Bury it deep underground.
• Shoot it into space.
• Bury it in the Antarctic ice sheet.
• Bury it in the deep-ocean floor that is
  geologically stable.
• Change it into harmless or less harmful isotopes.

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New and Safer Reactors

• Pebble bed modular reactor (PBMR) are smaller
  reactors that minimize the chances of runaway
  chain reactions.

Figure 16-21
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New and Safer Reactors

• Some oppose the pebble reactor due to
• A crack in the reactor could release
  radioactivity.
• The design has been rejected by UK and Germany
  for safety reasons.
• Lack of containment shell would make it easier
  for terrorists to blow it up or steal radioactive
  material.
• Creates higher amount of nuclear waste and
  increases waste storage expenses.

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NUCLEAR 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.
• There is a disagreement over whether to phase out
  nuclear power or keep this option open in case
  other alternatives do not pan out.

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How Would You Vote?

• Should nuclear power be phased out in the
  country where you live over the next 20 to 30
  years?
• a. No. In many countries, there are no suitable
  energy alternatives to nuclear fission.
• b. Yes. Nuclear fission is too expensive and
  produces large quantities of very dangerous
  radioactive wastes.