Coal-fired power plants present both benefits and risks. They provide a cheap, abundant source of electricity but also emit several hazardous air pollutants. Coal is burned in large furnaces to create steam that spins turbines connected to generators. The steam is then condensed and recycled. While coal supplies over 50% of US electricity and supports many jobs, the carbon dioxide, sulfur dioxide, nitrogen oxides and mercury released contribute to acid rain, smog, and health issues like heart attacks and respiratory illness. The future of coal may involve cleaner technologies and complying with environmental regulations to reduce these harmful emissions.
4. Coal Power Plant
Operation
Feedwater
Feedwater used in a steam boiler to transfer heat energy from the fuel
burning area to mech. Energy of spinning steam turbine
Boiler
Rectangular furnace, pulverized coal is blown in from fuel nozzles at 4
corners. The coal then burns quickly and forms a fireball at the center
(seriously, a fireball!!!).
5. Coal Power Plant
Operation
Steam Turbine Generator
Is a series of steam turbines interconnected to each other and
then a generator
Steam Condenser
Steam enters from the turbine generator and is pumped into the
bottom of the condenser, where pumps recycle the condensed
steam from the feedwater
Stack
Releases process emissions.
7. Pros of Coal
Power
Cheap
Cheaper per unit energy than oil or natural gas
Will continue to be an important global resource
Abundance
Coal is the world’s most abundant fossil fuel
Sufficient reserves for the next 250 years
8.
9. Pros of Coal
Power
Electricity
Supplying approximately 50% of electricity to the US
Economy
Coal-mining stimulates over one million jobs in the U.S.
Coal contributes over $80 billion annually to the economy
10. Pros of Coal
Power
Efficiency
Larger power plants are more efficient
38% of the chemical energy is converted to energy
Safe
safest fossil fuel to transport, store and use
scrubbers
11. Cons of Coal
Power
o Coal-Fired Power Plants are the largest contributor of
hazardous air pollutants.
o Sulfur dioxide (SO2)
o Nitrogen Oxide (NOx)
o Carbon Dioxide (CO2)
o Mercury
12. Effects on the
environment and Human health
CO2 ~ carbon dioxide pollution, making energy use the single largest
source of greenhouse gases in the U.S. and the world
13. Effects on the
environment and Human health
SO2
o Sulfur dioxide combined with nitrogen
oxide react with water and oxygen in the
atmosphere to form acidic compounds,
which can mix with natural precipitation
and fall to the earth as acid rain.
o Sulfur dioxide can also combine with
nitrogen oxide and other particles to form
particulate matter.
o trigger heart attacks and strokes
o lead to cardiac arrhythmia
(irregular heartbeat)
o respiratory irritation, and worsen
asthma.
o premature death (Both short-term
and long-term exposure)
14. Effects on the
environment and Human health
NOx
When nitrogen oxide (chemically) reacts with volatile organic
compounds (VOC’s) and sunlight ground-level ozone or smog is
formed.
An estimated 140.5 million
Americans live in areas with
unhealthy levels of smog according
to the The American Lung
Association.
15. Effects on the
environment and Human health
Mercury
One of the most dangerous pollutants released into the air
through the exhaust system when coal is burned.
16. Future of Coal
Economy
US economy relies on coal importation and exportation
The demand for coal usage to provide electricity will continue
to grow
17. Future of Coal
Clean coal technology
A new generation of coal-burning power plants with energy processes that
reduce air emissions and other pollutants.
Clean Air Acts
Coal power plants technology
must adapt to the changing
political climate towards
environmental issues.
Editor's Notes
Power plants emit 40% of total U.S. carbon dioxide pollution, the primary global warming pollutant.
Although coal-fired power plants account for just over half of the electricity produced in the U.S. each year, they have been responsible for over 83% of the CO2 pollution since 1990.
In the U.S., coal-fired power plants are the single largest source of SO2 pollution (66%)
and the second largest source of NOx pollution.
Coal-fired power plants are the largest single man-made source of mercury pollution in the U.S.
