Chapter 10: Fossil Fuels
Fossil Fuels
Fossil fuels are composed of partially
decayed remnants of organisms.
They are nonrenewable resources.
• We have a finite (limited) amount that is
being depleted
• Produce pollutants such as CO2, CO,
SO2, NO3
A. How Fossil Fuels Were
Formed
• Fossil fuels were formed in vast swamps that were
filled with plant species that had long been extinct.
• They decayed little after death since they were
covered with water.
• Over time, more and more dead plants built up and
as a result, layers of sediments accumulated,
forming layers that covered the plant material into
a carbon-rich rock called coal.
Coal
• This substance was formed when partially
decomposed plants were exposed to large
amounts of heat and pressure for eons (long
periods of time).
• Coal produces more CO2 emissions per unit
of heat than other fossil fuels.
Coal
• Formed when partially decomposed plants
were exposed to large amounts of heat and
pressure for long periods of time.
• Produces more CO2 emissions than any
other fossil fuel.
Types of Coal
• Lignite-soft coal that is low in sulfur and produces
less heat in comparison to other grades of coal
• Sub-bituminous-intermediate grade coal between
lignite and bituminous. Low hear value and sulfur
content.
• Bituminous- “soft coal” that is high in sulfur and
produces lots of heat
• Anthracite- “hard coal” that is low in sulfur and
produces the most heat and less pollution
Coal Reserves
• Coal is present in greater quantities than oil
or natural gas.
• Present coal reserves could last 200 years at
our present rate of consumption however
the harm to the environment would be more
substantial.
Mining of Coal
• Subsurface mining – underground coal mining that
is dangerous and unhealthy. Can cause black lung
disease.
• Surface mining-disturbs large land areas and is
expensive to restore the land. Advantages include
it being healthier , a better extraction of coal, and
less expensive. On the other hand, it disrupts the
land more than subsurface mining.
Mining of Coal
• In Surface mining the use of draglines to
remove mountain tops is one of the most
destructive types of surface mining.
• Strip Mining is the worst type of surface
mining. It creates spoil banks or hills of
loose rock.
Problems with mining coal
•
•
•
1) Landslides – They occur on hills that were
unstable due to the lack of vegetation.
2)Can cause black lung disease.
3) Acid mine drainage – This is produced when
rainwater seeps through iron sulfide minerals
exposed in mine wastes and carries sulfuric acid to
nearby lakes and streams.
4) Mountaintop removal – The dragline takes huge
chunks out of a mountain to reach the coal located
below.
Surface Mining
Control & Reclamation Act (SMCRA)
• Requires that surface-mined lands be
restored to make the land usable again.
• Was passed due to carbon dioxide emissions
from coal, inability to reduce or eliminate
CO2 from combustions of coal, and there
was acid deposition from soft coals that
contain sulfur.
Controlling Sulfur
Fluidized-bed combustion is a cleaner coalburning process that removes sulfur from
coal combustion (but not CO2).
• Scrubbers can also reduce sulfur escaping
from coal combustion but not the CO2.
These are often placed in smokestacks to
reduce emissions.
Cleaner ways to mine coal
• Resource recovery makes scrubbers more
desirable
Oil & Natural Gas
• Occur in structural traps such as anticlines,
the upward folding of rock layers, and salt
domes, underground columns of salt.
• Will probably be gone by the end of the 21st
century
• Mostly located in the Middle East
• Oil was formed when large numbers of microscopic
aquatic organisms died and settled in the sediments.
• Their decomposition depleted the small amount of O2 that
was present in the sediments.
• The resultant oxygen-deficient environment prevented
further decomposition and the dead remains were covered
and buried deeper into the sediments.
• The heat and pressure aided in the conversion of these
remains to hydrocarbons, known as oil.
Energy Consumption in Highly Developed and Developing Countries
Oil & Natural Gas
•Energy Policy & Conservation Act in 1975
as a result of problems with Oil
dependency.
• The Strategic Petroleum Reserve was
created which contains up to one billion
barrels of oil stored in Salt mines along the
Gulf of Mexico.
Environmental problems related to
Oil & Natural Gas
• 1989 Exxon Valdez was the largest spill in U.S. history
• 1991 Persian Gulf War “spill” (20x larger than the Exxon
Valdez spill)
• CO2 from Oil and natural gas combustion releases copious
amounts of CO2.
• Nitrogen Oxides and sulfur oxides are also released from
the combustion of Oil and Natural Gas. (acid rain)
Exxon Valdez Oil Spill
• The Exxon Valdez spilled 260,000 barrels of
crude oil into the Prince William Sound
along the coast of Alaska. This led to a
decline in bird populations, sea otter
populations, and the salmon migration was
disrupted. To clean up, they mechanized
stream cleaning and rinsing, which killed
shoreline organisms. They left the area with
contaminated shorelines.
Exxon Valdez Picture
Exxon Valdez
Exxon Valdez Picture
Persian Gulf Oil Spill
• In the Persian Gulf oil spills, crude oil was
dumped into the Persian Gulf. Many oil
wells were set on fire, and lakes of oil
spilled into the desert around the burning oil
wells. Cleanup efforts along the coastline
and the desert were hampered by the war.
Law because these spills
• The Oil Pollution Act of 1990-This legislation is
liable for damages to natural resources resulting
from a catastrophic oil spill, including a trust fund
that pays to clean up spills when the responsible
party in unable to.
• This act also requires double hulls on all oil tankers
that enter the U.S. waters by 2015.
Case in Point: The Arctic
National Wildlife Refuge
Alternatives
•
Synthetic fuels like tar sands (oil sands),
oil shales, gas hydrates, liquid coal, and coal
gas.
•
Coal gasification: Converts solid coal into
Methane by heating and mixing with steam.
•
C + H2O  CH4 + CO2
•
Coal liquefaction: process that produces a
liquid fuel that burns cleaner than solid coal.
• These can have some of the same
undesirable effects that fossil fuels have.
Move towards conservation (Car pooling,
insulation in homes, efficient automobiles,
light bulbs, & appliances.
55mph speed limit designed to reduce
pollution and use of fossil fuels as well
as safety 
Energy Efficiency
• SUV’s (Sport Utility Vehicles) use large amounts of
gasoline and other petroleum products.
Review
• 1) The world’s largest oil spill was the Persian
Gulf
• 2) Oily rocks that can be crushed and heated to
produce oil is oil shale.
• The most common type of coal is bituminous coal.
• Most of the oil reserves is in the Middle East
• The most abundant fossil fuel is coal
• Anthracite coal burns the hottest and produces the
least pollution.
Review
• Increasing the average global temp. due to increasing
amounts of CO2 in the atmosphere is global warming.
• Petrochemicals can be used to produce a variety of
everyday products.
• Technology used to remove sulfur oxides from smoke
stack emissions are scrubbers.
• Oil produces few sulfur oxides, but lots of nitrogen oxides
• Nitrogen oxide emissions are produced mainly by
automobiles
• Acid precipitation is linked to the worldwide forest
decline.
• Matching:
a. burns a coal-1imestone mixture; reduces pollution
1. hydrocarbons –
b. a synfuel abundant in Venezuela and Alberta, Canada
2. highwalls
c. using natural gas to produce electricity and generate steam
for water and space heating
3. scrubbers
d. cliffs of excavated rock at a surface mine
4. resource recovery
e. desulphurization systems; reduce coal's sulfur emissions
5. fluidized-bed combustion
f. a liquid composed of many hydrocarbon compounds
6. petroleum
g. used for home lighting and heating until replaced by oil
and natural gas
7. liquefied petroleum gas
h. molecules that make up oil
8. cogeneration
i. underground, ice-encrusted natural gas
9. anticline
j. rock strata, folded upward, that may trap oil or natural gas
10. salt dome
k. creates a marketable product from industrial waste
11. tar sands
1. used mainly for heating and cooking in rural areas
12. oil shales
m. an underground column of salt that may trap oil or natural
gas
13. gas hydrates
14. coal gas
n. a synfuel that is not yet cost-efficient to utilize