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Nonrenewable Energy - Fossil Fuels
“Our civilization runs by burning the remains of humble creatures who inhabited the Earth hundreds of
millions of years before the first humans…”
- Carl Sagan
2. ⚫Nonrenewable energy resources
are ones that do not replenish
within the timeframe of human
society.
⚫ Fossil fuels and nuclear power.
⚫Fossil fuels are forms of
nonrenewable energy that arise
from the remains of living
organisms over millions of years.
⚫ Coal, oil, and natural gas.
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Nonrenewable Energy
3. ⚫Coal is a hard, blackish substance that is formed from plant matter
that has been highly compressed and pressurized.
⚫ When the organic matter is compressed, its carbon content increases,
resulting in a greater energy content.
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Coal
4. ⚫Most coal formed
during the
carboniferous era,
which lasted from
about 360-300
million years ago.
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5. ⚫During the carboniferous
period, much of the
Earth experienced a
tropical climate.
⚫ The average temperature
was about 68°F, compared
to an average of 55.5°F in
the 20th century.
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6. ⚫Fern-like trees evolved the ability to
use a tough fiber called lignin to
grow tall and stay upright, allowing
them to outcompete neighboring
trees for sunlight.
⚫ The trees had a shallow root system,
causing them to fall over easily.
⚫ Bacteria and fungi had not yet evolved
the ability to digest lignin, so dead
trees did not decompose.
⚫The warm climate and
invulnerability to insects and fungi
significantly increased primary
productivity of forests.
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Drawing by Robert Krulwich
7. ⚫Over the next several million years, photosynthesis rates surpassed
those of combustion and respiration, altering the carbon and
oxygen cycles:
⚫ Atmospheric oxygen levels increased (from 21% to 35%)
⚫ Atmospheric carbon dioxide levels decreased (from 1500ppm to 350ppm)
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8. ⚫The decrease in atmospheric carbon dioxide weakened the greenhouse
effect, causing the global climate to become colder and a glacial
expansion.
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9. ⚫Modern coal deposits line up with the locations of largest
carboniferous swamps – North America, Eastern Europe, and Asia.
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10. ⚫Coal mining
companies look for
coal seams – layers of
coal within rock that
are thick enough to be
profitably mined.
⚫ Surface mining
techniques are used if
the coal is not too deep
underground.
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Coal Extraction
11. ⚫Open-pit mining is where
large holes are dug into
the earth and the
minerals removed.
⚫Strip mining actually
carves away horizontal
beds of coal deposit close
to the surface.
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12. ⚫Mountaintop removal uses explosives to blow up entire
mountaintops to allow surface mining of coal seams underneath.
⚫ The dislodged soil and rock, called spoil, is deposited into nearby valleys
⚫ Mountaintop removal changes mountain ecosystems so much that it can be
seen from satellite.
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14. ⚫Water can seep
through coal mines,
dissolving minerals
and creating acid mine
drainage.
⚫ Acidic, metallic, and
toxic to many animals
and plants.
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Environmental effects of coal mining
16. ⚫Workers in underground mines are exposed to high amounts of coal
dust, which can eventually lead to black lung disease.
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Normal lung tissue.
Mild case of Black Lung disease. Severe case of Black
Lung disease.
17. ⚫Oil is a carbon-rich liquid
found within rock strata
millions of years old.
⚫ Most oil deposits begin in
warm shallow seas so
productive that organic
material formed faster than it
could decompose.
⚫ The organic matter was
buried, heated, and
pressurized, becoming oil.
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Oil
18. ⚫The present day
distribution of oil
generally lines up
with those
productive shallow
seas.
⚫ Middle East,
Western U.S. and
Canada, Russia
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19. ⚫Oil can be pumped
directly out of the
ground without the
need for mining.
⚫ A long drill creates a
borehole that is then
lined with cement and
steel.
⚫ Collection pipes and
valves extract the oil.
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Oil Extraction
20. ⚫The ease of transporting oil has enabled drilling at very remote
locations.
⚫ Prudhoe Bay in Alaska, the Gulf of Mexico
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21. ⚫As a liquid, oil can also escape more easily, forming an oil spill.
⚫Oil spills are devastating to marine life.
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22. ⚫Oil penetrates through
the fur and feathers of
birds and mammals,
reducing their ability to
fly, float, and insulate
themselves.
⚫Benthic organisms, living
at the bottom of the sea,
can be suffocated.
⚫Directly toxic to fish and
plankton.
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Natural Gas
⚫Natural gas is a
flammable mixture of
gases, including
methane (CH4).
⚫As a gas, it is more
difficult to extract,
contain, and transport.
⚫ Many oil drillers will
burn off methane
deposits instead of
collecting them,
creating a gas flare.
24. ⚫Hydraulic fracturing, or “fracking”, is a controversial technique used to
extract natural gas from rock formations that are normally
impermeable.
⚫ Shale is the most common rock that contains methane.
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Hydraulic Fracturing
25. ⚫The Marcellus Shale is a
large underground shale
formation that contains an
estimated 88 trillion cubic
feet of natural gas.
⚫ Prior to 2008, these deposits
were unknown.
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26. ⚫First, a well is drilled
down, then horizontally
into the shale formation.
⚫A mixture of water and
other chemicals called
fracking fluid is pumped
in.
⚫ The pressure created from
this fluid causes the rock
formation to fracture.
⚫Sand is injected
afterwards to fill the
cracks, because it is more
permeable and allows the
methane to seep out.
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27. ⚫There are two big issues that
make hydraulic fracturing
controversial.
⚫ Millions of gallons of water are
needed to “frack” the well.
⚫ The water that returns back to
the surface, called flowback
wastewater, is contaminated
with minerals, fracturing fluid
chemicals, and natural gas itself.
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Water trucking containers, Dimock,
Pennsylvania.
28. ⚫Hydraulic fracturing has been issued many exemptions from Federal
environmental laws:
⚫ National Environmental Policy Act: Exempted from issuing certain
environmental impact reports before drilling.
⚫ Clean Air Act: Exempted from emission limits passed in the 1990 amendments.
⚫ Clean Water Act: Exempted from pollution from stormwater runoff.
⚫ Safe Drinking Water Act: Exempted from a rule restricting underground
injection of waste.
⚫ Resource Conservation and Recovery Act:
Exempted from certain hazardous waste
rules.
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Water collected from a well in rural
Bradford County, Pennsylvania.
29. ⚫Coal is primarily used as a source of heat for electricity generation.
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Applications of Fossil Fuels
Sahiwal Coal power
project, Punjab, India.
30. ⚫The boiler burns
coal, converting
its chemical
potential energy
of coal into
mechanical
kinetic energy of
steam.
⚫ Pollution is
released by the
stack.
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31. ⚫Steam generated
by boiling water
is passed through
a series of large
fan blades called
a turbine.
⚫ The kinetic
energy of steam
is converted to
mechanical
energy.
⚫A condenser
cools the steam
back into liquid
water.
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32. ⚫The spinning of
the turbine
blades spins a
generator, which
moves a magnet
near a charged
wire, generating
an electric
current.
⚫The electricity is
delivered
through a series
of large
transmission
wires.
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33. ⚫A cooling tower releases excess heat in the form of steam.
⚫ No actual air pollution is emitted, unlike the stack.
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34. ⚫Coal plants are generally located near streams or bodies of water to
ensure a constant supply of coolant water to replace the lost steam.
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Oak Creek Power Plant, located near Milwaukee, Wisconsin.
35. ⚫The residual ash is
mixed with water to
minimize dust, then
pumped into an ash
storage pond.
⚫ The ash is highly toxic,
containing heavy metals
and other toxins.
⚫ Eventually, 70-80% of
this ash is disposed of in
landfills. The rest is
used in concrete,
asphalt, and other
applications.
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Power plant and coal ash ponds,
Asheville, North Carolina.
36. ⚫Crude oil is separated in a process called
distillation, where it is gradually heated
and components are removed based on
boiling point.
⚫ Low boiling point compounds, like gasoline,
are removed first.
⚫The majority of the compounds derived
from oil are used for transportation fuel.
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37. ⚫Natural gas is either used as a source of household heat or burned for
electricity generation.
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38. ⚫Each fossil fuel has benefits and drawbacks as an energy source.
⚫In terms of pollution, coal is the dirtiest of the three fossil fuels, with
natural gas being the cleanest.
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Comparing Fossil Fuels
39. ⚫Energy returned on investment (EROI) is a ratio that measures the relative
cost and difficulty of extracting a specific resource.
⚫ EROI = Energy returned / Energy invested
⚫ Lower ratios indicate that the resource is more difficult and expensive to extract.
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40. ⚫The minimum EROI needed by an industrial society to function is 5-9.
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41. ⚫The reserves-to-production ratio estimates how many of a resource
we have left at current rates of use.
⚫ R/P Ratio = Total remaining reserves / Annual Rate of Production
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