Chapter 11
Fossil Fuels
Lecture Outline:
I. Energy Sources and Consumption
A. Just a few hundred years ago, almost all energy used by people was derived
from local energy sources (agriculture, wind and water)
i. People relied on their own physical energy and the energy of animals
to do work
ii. These energy sources were limited by energy density, the amount of
energy contained within an energy source
B. Today, 60% of the commercial energy consumed worldwide is used by high
developed countries (HDCs)
i. People in HDCs rely on energy consuming machines to do work
ii. The larger energy input is one reason the agriculture productivity of
HDCs is greater than that of developing countries
iii. Additional energy demands may be met by increased energy efficiency
C. An increase in economic development is usually accompanied by a rise in per
capita energy consumption
D. In the U.S., industry (production of materials) accounts for 42% of energy
consumption, 33% is used to make buildings and/or homes comfortable, and
25% is used primarily in transportation
E. Energy for China
i. In 2004, China became the world’s second largest importer of oil
1. China currently dominates international concerns over global
climate warming
2. In 2009, China will likely pass the U.S. as the top CO2 emitter
II. Fossil Fuels
A. Energy is obtained from a variety of sources, including fossil fuels (coal, oil,
and natural gas), nuclear reactors, biomass, solar and other alternative energy
sources (water, wind, etc.)
i. Fossil fuels supply most of the energy required in North America
ii. They are nonrenewable resources; formation does not keep pace with
current use
B. How fossil fuels are formed
i. Coal was formed from the remains of ancient plants that lived millions
of years ago
ii. Oil was formed from the remains of ancient microscopic aquatic
organisms
iii. Natural gas is composed primarily of methane and was created in
much the same way as oil, except at higher temperatures
III. Coal
A. In the 18th century, coal replaced wood as the dominant fuel in the Western
world
B.
C.
D.
E.
F.
i. Coal powered the steam engine and supplied the energy for the
Industrial Revolution
ii. Today it is used to produce electricity and steel
iii. Coal consumption has surged in recent years in China and India
Lignite, subbituminous coal, bituminous coal, and anthracite are the four most
common grades of coal
i. Lignite is a soft, moist coal that produces little heat and is often used to
power electric power plants
ii. Subbituminous coal has a relatively low heat value and sulfur content,
and is also used in coal-fired electrical power plants
iii. Bituminous (soft) coal produces substantially more heat that the lignite
or subbituminous, but also contains a higher sulfur content; it is used
extensively in electric power plants
iv. Anthracite (hard) coal is the highest grade of coal and produces the
fewest pollutants per unit of heat released (due to low sulfur content);
it has the highest heat-producing capacity of any grade of coal
Coal reserves
i. Coal is the most abundant fossil fuel in the world, and is found
primarily in the Northern Hemisphere
ii. World coal reserves could last more than 200 years at the present rate
of consumption
Coal mining
i. Surface mining extracts the mineral and energy resources near Earth’s
surface by first removing soil, subsoil, and overlying rock strata
1. It is used to obtain 60% of the coal mined in the U.S
2. It is often cheaper, safer, and generally allows more complete
removal of coal from the ground
3. It does, however, have the potential to cause more serious
environmental problems
ii. Subsurface mining extracts the mineral and energy resources from
deep underground deposits
Safety problems associated with coal
i. During the 20th century, more than 90,000 American coal miners died
in mining accidents
ii. Miners have increased risk of cancer and black lung disease
Environmental impacts of the mining process
i. Prior to 1977 (SMCRA – the Surface Mining Control and Reclamation
Act), abandoned surface coal mines were usually left as large open pits
or trenches and streams were polluted with sediment and acid mine
drainage
ii. The SMCRA requires coal companies to restore areas that have been
surface mined, requires permits and inspections of active coal mine
operations, and prohibits coal mining in sensitive areas
iii. Mountaintop removal is one of the most land-destructive types of
surface mining; it uses a dragline to remove the mountain top to reach
the coal below
G. Environmental impacts of burning coal
i. The Earth’s CO2 equilibrium has been disrupted by the enormous
amounts of CO2 produced through fossil fuel consumption this past
century
ii. This, in turn, has lead to a rise in global temperature and various
environmental issues associated with higher temperatures
1. Melting of polar ice caps
2. Rising sea levels
3. Future flooding of coastal areas, increasing coastal erosion and
associated violent storms
iii. Coal burning generally contributes more air pollutants (including CO2)
than does burning either oil or natural gas (i.e., mercury, sulfur oxides,
nitrogen oxides, and acid deposition)
H. Making coal a cleaner fuel
i. It is possible to reduce sulfur emissions associated with the
combustion of coal by installing scrubbers to clean the power plant’s
exhaust
1. Modern scrubbers remove 98% of the sulfur and 99% of the
particulate matter in smokestacks
2. Desulfurization systems are very expensive
ii. Selling the sulfurs or metals removed from polluted emissions as a
marketable product is called resource recovery
iii. The Clean Air Act Amendments of 1990 required the nation’s 111
dirtiest coal-burning power plants to cut sulfur dioxide emissions
1. This cut emissions by 3.8 million metric tons nationwide
2. The second phase of this amendment called for 200 additional
power plants to make SO2 cuts by 2000
a. This reduced the total annual emission by 10 million
metric tons nationwide
b. A nationwide cap on SO2 emissions was imposed after
2000
iv. Clean coal technologies are new methods being developed for burning
coal that will not contaminate the atmosphere with sulfur oxides and
will significantly reduce nitrogen oxide contamination
1. Fluidized-bed combustion and coal gasification and
liquefaction are two new clean coal technologies
2. These new technologies have little impact on reducing CO2
emissions
IV. Oil and Natural Gas
A. Beginning in the 1940s, oil and natural gas became increasingly important as
energy sources due to easier transport and cleaner burning
i. In 2005, oil and natural gas supplied 63% of the energy used in the
U.S.
ii. In 2004, oil and natural gas supplied 60.6% of the world’s energy
B. Petroleum (crude oil) is separated into gases, gasoline, heating oil, diesel oil,
and asphalt during the refining process
C. Oil is used to produce petrochemicals used in fertilizers, plastics, paints,
pesticides, medicines, and synthetic fibers
D. Natural gas is separated into propane, butane, and ethane; it costs four times
more to transport through pipelines than crude oil
i. Liquefied petroleum gas (propane and butane) is used as fuel for
heating and cooking
ii. Natural gas is used to produce both electricity and steam in a process
called cogeneration
iii. Natural gas as a fuel for trucks, buses, and automobiles offers
significant environmental advantages over gasoline or diesel
E. Exploration for oil and natural gas
i. Oil and natural gas deposits are usually discovered indirectly by the
detection of structural traps; geological analysis to find structural
traps is extremely expensive
ii. Many important oil and natural gas deposits are found in association
with salt domes
F. Reserves of oil and natural gas
i. Distribution is uneven; a large share of total oil deposits are clustered
relatively close together (Persian Gulf region, Venezuela, Mexico,
Alaska, etc.)
ii. Almost half of the world’s proved recoverable reserves of natural gas
are located in Russia and Iran
iii. Many countries engage in offshore drilling for oil despite problems
such as storms at sea and the potential for major oil spills
G. How long will oil and natural gas supplies last?
i. Some experts think that global oil production has already reached Peak
Oil (aka Hubberts Peak), others believe it will be reached around 2035
ii. About 80% of current production comes from oil fields discovered
before 1973, and most of these have started to decline in production
H. Global oil demand and supply
i. The U.S. currently imports more than half of its oil; this dependence
has potential international security implications as well as economic
impacts
ii. The imbalance between oil consumers and oil producers will probably
worsen in the future because the Persian Gulf region has much higher
proven reserves than other countries
I. Environmental impacts of oil and natural gas
i. Problems that result from burning fuels (combustion)
1. Every gallon of gas burned in a car releases an estimated 9kg
of CO2 into the atmosphere; global warming results from
increased CO2 in the atmosphere
2. Increased acid deposition, photochemical smog, and increased
particulate matter result from combustion
ii. Problems such as serious spills along transportation routes are
involved in obtaining fuels
V. Synfuels and Other Potential Fossil Fuel Resources
A. Synfuels are fuels that are similar or identical to the chemical composition of
oil or natural gas (i.e., tar sands, oil shales, gas hydrates, liquefied coal, and
coal gas)
B. Synfuels are more expensive to produce than fossil fuels
C. Environmental impacts of synfuels
i. Synfuels have many of the same undesirable effects as fossil fuels
1. Release of CO2 and other pollutants into the atmosphere
2. They require large amounts of water during production; limited
usefulness in arid lands
ii. Large areas of land would have to be surface mined to recover the fuel
in tar sands and oil shales
VI. The U.S. Energy Strategy
A. A comprehensive national energy policy should consider the following
elements
i. Increase energy efficiency and conservation
ii. Secure future fossil fuel energy supplies
iii. Develop Alternative Energy Sources
iv. Meet the first three objectives without further damage to the
environment
B. How politics influences the national energy policy
i. The Energy Policy Act of 2005 focuses largely on supporting energy
research for fossil fuels
ii. Subsidies continue