FOSSIL FUELS III
Coal
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Formed from ancient plants.
Coal beds were prehistoric swamps.
Can be considered to be “stored” solar energy.
Photosynthesis:
CO2 + H20 + solar energy  carbohydrates + O2
We can also run the process backwards and
burn carbs to get energy, water and
carbondioxide.
• Normally when a plant dies it decomposes.
• If there is not enough Oxygen, it can’t
completely decompose, thus we get a slow
accumulation of energy.
• In a swamp, the bacteria that decompose the
plants also use up the Oxygen.
• Coal found today formed between 1 and 440
million years ago.
Major Coal Forming Periods
• Carboniferous and Permian 360 to 250 MYA
– High quality bituminous and anthracite
• Upper Cretaceous to Miocene 100 to 5 MYA
– Low quality subbituminous and lignite coals
• Quaternary 2.6 MYA to present
– peat
• Steps to becoming coal:
• Peat
• Lignite (brown coal)
• Subbituminous
• Bituminous
• Anthracite
• The major difference is the percentage of the
coal that is carbon. Higher carbon
concentration means better quality coal. (in
general)
• Coal progresses through the stages with increasing
pressure and temperature.
Type
% Carbon
Lignite
30
Energy Content
(MJ/kg)
11.6 – 16.3
Subbituminous
40
18.6 – 23.3
Bituminous
50 - 70
25.6 - 34.8
Anthracite
90
32.5
Oil
85
46
Coal Classification
Which type of coal provides the
most energy/kg?
1. Lignite
2. Bituminous
3. Anthracite
33%
1
33%
2
33%
3
• The largest amount of US coal is Bituminous.
• Approximately 1% is Anthracite. (Found in
Pennsylvania.)
• Many coal veins have a high sulfur content.
– Significant contributor to acid rain.
– S+O2SO2
– SO2 combines with water in atmosphere to form
sulfuric acid.
– Limits the use of those coals
• Coal has uranium & thorium: radioactive
– Concentrated when coal is burned
• Other contributions.
• Mercury
• Arsenic
• Selenium
Union Pacific Big Boy
Coal Mining
• Coal veins can be 1in to 400 ft thick.
• Must be at least 2 ft thick to make mining
profitable.
• According to CNN, underground mining is the
most dangerous occupation in America.
• Bureau of Labor Statistics underground mining
is the second most dangerous occupation in
America (by rate).
Coal Mining
• Tunneling – 40%
• Surface mining – 60%
– Removing overburden to get to coal
• Strip mining
• Mountaintop removal
Types of Coal Mining
Tunnel Mining
Strip Mining
Mountain Top Removal
https://www.youtube.com/
watch?v=p5RcbPZXUZo
Which type of coal mining is
predominant?
1. Tunnel mining
2. Surface mining
3. Placer mining
33%
1
33%
2
33%
3
Should Mountain Top Removable
be allowed in the U.S.?
1. Yes
2. No
50%
1
50%
2
US Coal Reserves by Type
Coal Reserves Sulfur Content
Coal Reserves Sulfur Content
World Coal Reserves
Proved Coal Reserves (2006)
Brazil
Poland
Kazakhstan
Ukraine
South Africa
Australia
India
China
Russia
United States
0
50000
100000
150000
TOTAL
(million tonnes (teragrams)
200000
250000
Coal Production
Production of Coal 2006
Total World
Poland
Indonesia
Germany
South Africa
Russia
Australia
India
USA
China
0
1000
2000
3000
4000
million tonnes
5000
6000
7000
Which is the current high producer of coal?
1. Russia
2. China
3. USA
4. Germany
25%
1
25%
2
25%
3
25%
4
Chinese SY Mikado 2-8-2
A thick shroud of haze lingers over China, turning the sky an opaque grey.
Beijing, China's capital, is situated under the densest portion of the smog
layer. The aerosol pollution can be seen blowing eastward across the Bo
Hai Bay and Yellow Sea reaching as far as North and South Korea and the
islands of Japan. (NASA)
Donora 1948
Coal
Consumption
Mix of Fuels in US
US Coal Production
• Estimated that we have enough reserves for
200-300 years at current production rates.
• Use may be expanded
– Replace aging oil/natural gas/nuclear electric
plants
– More demand for electrical energy
– Alternative uses such as coal gasification.
Should the use of coal in America
be expanded?
1. Yes
2. No
50%
1
50%
2