Mrs. Ashley's PowerPoint on chapter 12

Chapter 12
Nonrenewable Energy Resources
Nonrenewable Energy
Nonrenewable energy resources- fossil fuels
(coal, oil, natural gas) and nuclear fuels.
Modern society requires large quantities of energy that are
generated from the earth’s natural resources.
Primary Energy Resources: The fossil fuels(oil, gas, and
coal), nuclear energy, falling water, geothermal, and solar
Secondary Energy Resources: Those sources which are
derived from primary resources such as electricity, fuels
from coal, (synthetic natural gas and synthetic gasoline), as
well as alcohol fuels.
The laws of thermodynamics tell us two things
about converting heat energy from steam to
1) The conversion of heat to work cannot be 100 %
efficient because a portion of the heat is wasted.
2) The efficiency of converting heat to work
increases as the heat temperature increases.
Btu (British thermal unit) - amount of energy
required to raise the temperature of 1 lb of water
by 1 ºF.
cal (calorie) - the amount of energy required to
raise the temperature of 1 g of water by 1 ºC.
Commonly, kilocalorie (kcal) is used.
1 Btu = 252 cal = 0.252 kcal
1 Btu = 1055 J (joule) = 1.055 kJ
1 cal = 4.184 J
Energy Units and Use
Two other units that are often seen are the
horsepower and the watt. These are not units of
energy, but are units of power.
1 watt (W) = 3.412 Btu / hour
1 horsepower (hp) = 746 W
Watt-hour - Another unit of energy used only to
describe electrical energy. Usually we use
kilowatt-hour (kW-h) since it is larger.
quad (Q) - used for describing very large quantities
of energy. 1 Q = 1015 Btu
Energy Use
Commercial energy sources- those that are
bought and sold, such as coal, oil and natural
Subsistence energy sources- those gathered by
individuals for their own use such as wood,
charcoal and animal waste.
Changes in U.S. Energy Use
Energy resources removed from the
earth’s crust include: oil, natural gas,
coal, and uranium
Process of Energy Use
Overall Fuel Efficiency of
U.S. Automobiles
Electricity Generation
Electricity Generation
The burning fuel from coal transfers energy to
water, which becomes steam.
The kinetic energy contained within the steam
is transferred to the blades of a turbine, a large
device that resembles a fan.
As the energy in the steam turns the turbine,
the shaft in the center of the turbine turns the
This mechanical motion generates energy.
Energy Efficiency
Most coal burning power plants are about 35%
Cogeneration- using a fuel to generate
electricity and to produce heat.
Example- If steam is used for industrial
purposes or to heat buildings it is diverted to
turn a turbine first.
This improves the efficiency to as high as 90%.
Coal- a solid fuel formed primarily from the
remains of trees, ferns, and other plant
materials that were preserved 280-360 million
years ago.
Four types of coal ranked from lesser to greater
age, exposure to pressure, and energy content.
These four types are: lignite, sub-bituminous,
bituminous, and anthracite.
The largest coal reserves are in the United
States, Russia, China, and India.
Lignite: A brownish-black coal of low quality (i.e., low
heat content per unit) with high inherent moisture and
volatile matter. Energy content is lower 4000 BTU/lb.
Subbituminous: Black lignite, is dull black and generally
contains 20 to 30 percent moisture Energy content is 8,300
Bituminous: most common coal is dense and black (often
with well-defined bands of bright and dull material). Its
moisture content usually is less than 20 percent. Energy
content about 10,500 Btu / lb.
Anthracite :A hard, black lustrous coal, often referred to
as hard coal, containing a high percentage of fixed carbon
and a low percentage of volatile matter. Energy content
of about 14,000 Btu/lb. Powerpoint%5CCoal.ppt
Advantages and
Disadvantages of Coal
Contains impurities
Plentiful (300 years of use remaining)
Release impurities into air when
Easy to exploit by surface mining
Trace metals like mercury, lead, and
arsenic are found in coal
Technological demands are small
Combustion leads to increased levels
of sulfur dioxide and other air
pollutants into the atmosphere.
Economic costs are low
Ash is left behind
Easy to handle and transport
Carbon is released into the
atmosphere which contributes to
climate change
Needs little refining
Major threat to health
Acid Mine
The impact of mine
drainage on a
lake after
receiving effluent
from an
impoundment for
over 50 years
Relatively fresh tailings in an
The same tailings impoundment after
7 years of sulfide oxidation. The white
spots in Figures A and B are gulls.
Petroleum- a mixture of hydrocarbons, water,
and sulfur that occurs in underground
Oil and gasoline make this ideal for mobile
combustion, such as vehicles.
Formed from the remains of ocean-dwelling
phytoplankton that died 50-150 million years
Countries with the most petroleum are Saudi
Arabia, Russia, the United States, Iran, China,
Canada, and Mexico.
Oil in U.S.
• 2.3% of world
• uses nearly 30% of
world reserves;
• 65% for
• increasing
dependence on
Advantages and
Disadvantages of Petroleum
Convenient to transport and use
Releases carbon dioxide into
Relatively energy-dense
Possibility of leaks when extracted
and transported
Cleaner-burning than coal
Some water pollution
Low Cost with subsidies
Releases sulfur, mercury, lead, and
arsenic into the atmosphere when
Ample supply for about 50 years
When price is low discourages
alternate choices encourages waste
Natural Gas
Natural gas- exists as a component of
petroleum in the ground as well as in gaseous
deposits separate from petroleum.
Contains 80 to 95 percent methane and 5 to 20
percent ethane, propane, and butane.
Sources of Natural Gas
•Russia & Kazakhstan - almost 40% of
world's supply.
•Iran (15%), Qatar (5%), Saudi Arabia
(4%), Algeria (4%), United States (3%),
Nigeria (3%), Venezuela (3%);
•90–95% of natural gas in U.S. domestic
(~411,000 km = 255,000 miles of
billion cubic metres
Advantages and
Disadvantages Natural
Contains fewer impurities and
therefore emits almost no sulfur
dioxide or particulates
When unburned, methane escapes
into the atmosphere
Emits only 60% as much carbon
dioxide as coal
Exploration of natural gas has the
potential of contaminating
Ample supplies up to 150 years
Low cost with huge subsidies
Shipped across oceans as highly
flammable LNG
Other Fossil Fuels
Oil sands- slow-flowing, viscous deposits of
bitumen mixed with sand, water, and clay.
Bitumen (tar or pitch)- a degraded type of
petroleum that forms when a petroleum
migrates close to the surface, where bacteria
metabolize some of the light hydrocarbons and
others evaporate.
The Hubbert Curve
Hubbert curve- a graph that shows the point at
which world oil production would reach a
maximum and the point at which we would
run out of oil.
The Future of Fossil Fuel
If current global use continues, we will run out
of conventional oil in less than 40 years.
Coal supplies will last for at least 200 years,
and probably much longer.
• Burning any fossil fuel releases carbon dioxide into the
atmosphere and thus promotes global warming.
• Comparison of CO2 emitted by fossil fuels and nuclear
Nuclear Energy
Fission- a nuclear
reaction in which a
neutron strikes a
relatively large atomic
nucleus, which then
splits into two or more
Nuclear Reactors
Nuclear Reactors
Fuel rods- the cylindrical tubes that house the
nuclear fuel used in a nuclear power plant.
Nuclear power plants work by using heat from
nuclear fission to heat water. This water
produces the steam to turn the turbine, which
turns a generator.
Control rods- cylindrical devices that can be
inserted between the fuel rods to absorb excess
neutrons, thus slowing or stopping the fission
Advantages and
Disadvantages of Nuclear
No air pollution is produced
Possibility of accidents
Countries can limit their need for
imported oil
Disposal of the radioactive waste
Emits 1/6 as much pollution as coal
High cost even with high subsidies
Low environmental impact if no
Spreads knowledge for nuclear
Low net energy yield
Radioactive Waste
Radioactive waste- once the nuclear fuel can
not produce enough heat to be used in a power
plant but it continues to emit radioactivity.
This waste must be stored in special, highly
secure locations because of the danger to living
Radioactive Waste
High-level radioactive waste- the form used in
fuel rods.
Low-level radioactive waste- the protective
clothing, tools, rags, and other items used in
routine plant maintenance.
• April 26, 1986, reactor explosion (Ukraine) flung
radioactive debris into atmosphere
• Health ministry reported 3,576 deaths
• Green Peace estimates32,000 deaths;
• About 400,000 people were forced to leave their
• ~160,000 sq km (62,00 sq mi) contaminated
• > Half million people exposed to dangerous levels of
• Cost of incident > $358 billion
Three Mile Island
• March 29, 1979, a reactor near Harrisburg, PA lost
coolant water because of mechanical and human
errors and suffered a partial meltdown
• 50,000 people evacuated & another 50,000 fled area
• Unknown amounts of radioactive materials released
• Partial cleanup & damages cost $1.2 billion
• Released radiation increased cancer rates.
Nuclear fusion- the reaction that powers the
Sun and other stars. This occurs when lighter
nuclei are forced together to produce heavier
nuclei and heat is released.
Fusion is a promising, unlimited source of
energy in the future, but so far scientists have
had difficulty cotaining the heat that is