07-04-2011, 11:54 AM
Presented By:
Kristin Scheel
Alejandra Kuhn
Brianna Beconovich
Ryan Nester
COAL.ppt (Size: 889.5 KB / Downloads: 385)
Coal-Fired Power Plants
Types of Coal
Fossil fuel
It is a readily combustible black or brownish-black sedimentary rock
Coal Mining
Surface Mining
Strip Mining
Underground Mining
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!!!).
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.
Coal Power Plant Operation
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
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
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
Cons of Coal Power
o Coal-Fired Power Plants are the largest contributor of hazardous air pollutants.
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
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.
• Effects on the environment and Human health
NOx
o When nitrogen oxide (chemically) reacts with volatile organic compounds (VOC’s) and sunlight ground-level ozone or smog is formed.
Mercury
One of the most dangerous pollutants released into the air through the exhaust system when coal is burned.
Future of Coal
Economy
US economy relies on coal importation and exportation
The demand for coal usage to provide electricity will continue to grow
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.