Nonrenewable Energy

1
Chapter 16

• Nonrenewable Energy

2
How Long Will the Oil Party Last?

• Saudi Arabia could supply the world with oil for
  about 10 years.
• The Alaskas North Slope could meet the world oil
  demand for 6 months (U.S. 3 years).
• Alaskas Arctic National Wildlife Refuge would
  meet the world demand for 1-5 months (U.S. 7-25
  months).

3
ENERGY RESOURCES

• 99 of the energy we use for heat 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 the commercial energy we use comes from
  nonrenewable fossil fuels (oil, natural gas, and
  coal)

4
ENERGY RESOURCES

• Commercial energy use by source for the world
  (left) and the U.S. (right).

Figure 16-3
5
ENERGY RESOURCES

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

Figure 16-2
6
Net Energy Ratios

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

Figure 16-4
7
OIL

• Crude oil (petroleum) - 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 (lowers
  the net energy yield).
• Primary Recovery drill well pump out light
  crude
• Secondary recovery pump water into surrounding
  areas forces out heavier crude
• Tertiary recovery inject steam or CO2 takes
  1/3 barrel to get 1 barrel

8
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
9

• Eleven OPEC (Organization of Petroleum Exporting
  Countries) have 78 of the worlds proven oil
  reserves and most of the worlds unproven
  reserves.
• Global markets

Figure 16-6
10
U.S. Oil Supplies

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

http//www.eia.doe.gov/country/index.cfmEnergy
11
Oil Imports
12
OIL

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

Figure 16-7
13
CO2 Emissions

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

Figure 16-8
14
Oil Shales

• Kerogen - a solid combustible mixture of
  hydrocarbons in oil shales

Figure 16-9
15
Tar Sands

• Takes about 1.8 metric tons of oil sand to
  produce one barrel of oil most are too deep.

Figure 16-10
16
NATURAL GAS

• Natural gas 50 90 methane
• Sources above reservoirs of crude oil, coal
  beds, and bubbles of methane trapped in ice
  crystals (under arctic permafrost and beneath
  deep-ocean sediments)

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

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.
• Coal has the highest environmental impact
  (mercury, sulfur oxides, carbon oxides).

20
COAL

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

21
NUCLEAR ENERGY

• Isotopes of uranium and plutonium undergo
  controlled nuclear fission - 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 .
• Enriched to 3 - 5 U-235

22
Parts of Nuclear Reactor

• Core 35,000 50,000 fuel rods
• Uranium fuel 97 U-238 (non-fissionable) 3
  U-235 (fissionable)
• Control Rods absorb neutrons regulate rate
• Moderator slows down neutrons emitted keeps
  chain reaction going
• Coolant water, CO2 makes steam

23

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
24
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.
• After spent fuel rods have cooled considerably,
  they are sometimes moved to dry-storage
  containers made of steel or concrete.

Figure 16-17
25

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
26
What Happened to Nuclear Power?

• After more than 50 years of development and
  enormous government subsidies, nuclear power
  struggles due to
• Multi billion-dollar construction costs.
• Higher operation costs and more malfunctions than
  expected.
• Poor management.
• Public concerns about safety and stricter
  government safety regulations.

27
Chernobyl Nuclear Power Plant

• The worlds worst nuclear power plant accident
  occurred in 1986 in Ukraine (may be matched by
  Japan now).
• 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.

28
COAL VS. NUCLEAR

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

Figure 16-20
29
NUCLEAR ENERGY

• At least 228 large commercial reactors worldwide
  (20 in the U.S.) are scheduled for retirement by
  2012.
• Low-level waste must be stored for 100 500
  years
• High-level waste 10,000 24,000 years
• Yucca Mountain potential storage site of wastes

30
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.

31
New and Safer Reactors

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

Figure 16-21
32
Problems with Pebble Reactors

• 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.

33
Breeder Fusion Reactors

• Use U-238 convert it into Plutonium -239
• Create more energy than they consume
• Use liquid sodium as coolant used by France
• Fusion uses deuterium tritium to fuse at 100
  million degrees is not feasible yet.

34
PLANT VOGTLE BURKE COUNTY GA