Non-renewable Energy Resources

1
Non-renewable Energy Resources

• Chapter 16

2
Essential Question 3

• Differentiate between the following types of
  non-renewable energy resources oil, natural gas,
  coal, nuclear energy.

3
OIL

• Crude oil (petroleum) is a thick liquid
  containing hydrocarbons that we extract from
  underground deposits and separate into products
  such as gasoline, heating oil and asphalt.
• Only 35-50 can be economically recovered from a
  deposit.
• As prices rise, about 10-25 more can be
  recovered from expensive secondary extraction
  techniques.
• This lowers the net energy yield.

4
OIL

• Refining crude oil
• Based on boiling points, components are removed
  at various layers in a giant distillation column.
• The most volatile components with the lowest
  boiling points are removed at the top.

Figure 16-5
5
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 a slow
  decline, oil prices will rise and could threaten
  the economies of countries that have not shifted
  to new energy alternatives.

6
Important Moments in Oils History

• 1857 First Commercial Oil Well, Pennsylvania
• 1930 Oil costs 10 per barrel
• 1960 OPEC is formed so developing countries
  with most of the worlds known oil and reserves
  can get a higher price for their oil
• 1973-74 OPEC reduces oil imports to the west
  bans oil exports to the U.S. b/c of their support
  of Israel in the Yom Kippur War. Oil prices rise
  sharply, causing double-digit inflation and
  global recession
• 1981 Iran-Iraq war pushes global oil prices to
  a historic high
• 1990-91 Persian Gulf War to protect U.S. access
  to Saudi Arabian Kuwaiti oil supplies
• 2004 Second Persian Gulf War begins
• 2010-2030 worlds estimated oil reserves
  expected to peak

7
OIL

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

Figure 16-6
8

Trade-Offs
Conventional Oil
Advantages
Disadvantages
Ample supply for 4293 years
Need to find substitutes within 50 years
Low cost (with huge subsidies)
Artificially low price encourages waste and
discourages search for alternatives
High net energy yield
Easily transported within and between countries
Air pollution when burned
Low land use
Technology is well developed
Releases CO2 when burned
Efficient distribution system
Moderate water pollution
Fig. 16-7, p. 363
9
CO2 Emissions
Figure 16-8

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

10
Oil Sands Oil Shale

• Heavy and tarlike oils from oil sand and oil
  shale could supplement conventional oil, but
  there are environmental problems.
• Oil sand is a mixture of clay, sand,
• water and combustible organic
• material called bitumen
• Oil shales contain a solid
• combustible mixture of
• hydrocarbons called kerogen.
• High sulfur content.
• Extracting and processing produces
• Toxic sludge
• Uses and contaminates larges volumes of water
• Requires large inputs of natural gas which
  reduces net energy yield.

11
Keystone XL Pipeline

• To import tar sand oil from Canada to Texas for
  refining

12

Trade-Offs
Heavy Oils from Oil Shale and Oil Sand
Advantages
Disadvantages
Moderate cost (oil sand)
High cost (oil shale)
Large potential supplies, especially oil sands in
Canada
Low net energy yield
Large amount of water needed for processing
Easily transported within and between countries
Severe land disruption
Severe water pollution
Efficient distribution system in place
Air pollution when burned
CO2 emissions when burned
Technology is well developed
Fig. 16-10, p. 365
13
NATURAL GAS

• Natural gas, consisting mostly of 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.

14
NATURAL GAS

• Russia and Iran have almost half of the worlds
  reserves of conventional gas, and global reserves
  should last 62-125 years.
• Natural gas is versatile and clean-burning fuel,
  but it releases the greenhouse gases carbon
  dioxide (when burned) and methane (from leaks
  during extraction) into the troposphere.

15

Trade-Offs
Conventional Natural Gas
Advantages
Disadvantages
Ample supplies (125 years)
Nonrenewable resource
High net energy yield
Releases CO2 when burned
Low cost (with huge subsidies)
Methane (a greenhouse gas) can leak from pipelines
Less air pollution than other fossil fuels
Lower CO2 emissions than other fossil fuels
Difficult to transfer from one country to another
Moderate environmental impact
Shipped across ocean as highly explosive LNG
Easily transported by pipeline
Sometimes burned off and wasted at wells because
of low price
Low land use
Good fuel for fuel cells and gas turbines
Requires pipelines
Fig. 16-11, p. 368
16
Natural Gas Fracking
Potential for aquifer contamination
17
COAL

• Coal is a solid fossil fuel that is formed in
  several stages as the buried remains of land
  plants that lived 300-400 million years ago.

Figure 16-12
18

Energy from Coal
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
19
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 worlds 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.

20
COAL

• Coal is the most abundant fossil fuel, but
  compared to oil and natural gas it is
• not as versatile
• has a high environmental impact
• releases much more CO2 into the troposphere

Figure 16-14
21
COAL

• Coal can be converted into synthetic natural gas
  (SNG or syngas) and liquid fuels (such as
  methanol or synthetic gasoline) that burn cleaner
  than coal.
• Costs are high.
• Burning them adds more CO2 to the troposphere
  than burning coal.

22
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
23
NUCLEAR ENERGY

• When isotopes of uranium and plutonium undergo
  controlled nuclear fission, the 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.
• Enriched from natural 0.7 uranium-235 by
  removing uranium-238

24

Energy from Nuclear
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
25
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.

Figure 16-17
26
NUCLEAR ENERGY

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

Figure 16-17
27

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
Uranium-235 as UF6 Plutonium-239 as PuO2
Conversion of U3O8 to UF6
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
28
What Happened to Nuclear Power?

• After more than 50 years of development and
  enormous government subsidies, nuclear power has
  not lived up to its promise because
• Multi billion-dollar construction costs.
• Higher operation costs and more malfunctions than
  expected.
• Poor management.
• Public concerns about safety and stricter
  government safety regulations.

29
Chernobyl Fukushima

• Fukushima
• The worlds WORST nuclear disaster in 2011 in
  Japan
• Disaster caused by tsunami resulting from massive
  earthquake
• Chernobyl
• The worlds 2nd worst nuclear power plant
  accident occurred in 1986 in Ukraine.
• The disaster was caused by poor reactor design
  and human error.

30

Trade-Offs
Conventional Nuclear Fuel Cycle
Advantages
Disadvantages
Large fuel supply
Cannot compete economically without huge
government subsidies
Low environmental impact (without accidents)
Low net energy yield
High environmental impact (with major accidents)
Emits 1/6 as much CO2 as coal
Catastrophic accidents can happen (Chernobyl)
Moderate land disruption and water pollution
(without accidents)
No widely acceptable solution for long-term
storage of radioactive wastes and decommissioning
worn-out plants
Moderate land use
Low risk of accidents because of multiple safety
systems (except for 15 Chernobyl-type reactors)
Subject to terrorist attacks
Spreads knowledge and technology for building
nuclear weapons
Fig. 16-19, p. 376
31

Trade-Offs
Coal vs. Nuclear
Coal
Nuclear
Ample supply of uranium
Ample supply
Low net energy yield
High net energy yield
Low air pollution (mostly from fuel reprocessing)
Very high air pollution
Low CO2 emissions (mostly from fuel reprocessing)
High CO2 emissions
High land disruption from surface mining
Much lower land disruption from surface mining
High land use
Moderate land use
High cost (even with huge subsidies)
Low cost (with huge subsidies)
Fig. 16-20, p. 376
32
NUCLEAR ENERGY

• When a nuclear reactor reaches the end of its
  useful life, its 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 reactors are applying to extent their
  40-year license to 60 years.
• Aging reactors are subject to embrittlement and
  corrosion.

33
NUCLEAR ENERGY

• Building more nuclear power plants will not
  lessen dependence on imported oil and will not
  reduce CO2 emissions as much as other
  alternatives.
• The nuclear fuel cycle contributes to CO2
  emissions.
• Wind turbines, solar cells, geothermal energy,
  and hydrogen contributes much less to CO2
  emissions.

34
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.

35
New and Safer Reactors

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

Figure 16-21
36
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.

37
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.