Coal

1. Fossil Fuels
Coal
Coal Seam in Independence
Park in Marquette Heights, IL.
Power Lines from Coal Burning
Power Plant in Pekin, IL

2. Coal is cheap, plentiful and
dirty -- as cheap as dirt, as
plentiful as dirt, and as dirty
as dirt -- since after all, coal is
little more than dirt that burns.

3. U.S. Coal Overview
•United States' most abundant energy source.
•1.7 trillion tons of coal resources in the United
States.
•Potential reserves may be as high as 4 trillion
tons.
•20 percent of the total world's recoverable coal.
–By comparison, Saudi Arabia has about 23 percent of
the world's proven petroleum reserves.
•At current domestic consumption levels, this is
enough coal to last 300 years.

4. Formation of Coal

5. Formation of Coal
•The formation of coal begins in a waterlogged
environment (swamps and bogs) where plant
debris accumulated.
•In such an environment, the accumulation of plant
debris exceeds the rate of bacterial decay of the
debris.
•The bacterial decay rate is reduced because the
available oxygen in organic-rich water is
completely used up by the decaying process.
•Anaerobic (without oxygen) decay is much slower
than aerobic decay.

6. Formation of Coal
•Peat is an accumulation of
partially decayed
vegetation matter.
•For the peat to become
coal, it must be buried by
sediment.
•10 vertical feet of original
peat material is required to
produce 1 vertical foot of
coal.

7. Formation of Coal
Phase 1. Aerobic decay
•In the first few inches of peat, aerobic
(oxygen needing) bacterial decay
reduces the volume by as much as
50%.
•Because the water is stagnant and the
peat is almost impermeable, the
bacteria soon use up all the available
oxygen and die, ending the first stage of
decay.

8. Formation of Coal
Phase 2. Anerobic decay
•A second type of bacteria exists in the
swamp that requires no oxygen. These
anerobic bacteria continue the decay
process reducing the volume still
further.
•Anerobic decay produces more acids
and when the acidity gets too high, it
kills off the remaining bacteria ending all
decay.

9. Formation of Coal
Phase 3. Bituminization
•After the bacterial decay stages, the peat
must be buried under thousands of feet of
sediment that provides an insulating
blanket trapping the natural heat rising to
the surface.
•Once the temperature reaches 100°C,
(212°F) the bituminization process begins.
•Chemical reactions drive off water, oxygen
and hydrogen which raises the percentage
of carbon.

10. Formation of Coal
•The stages of this trend proceed from plant
debris through peat, lignite, sub-bituminous
coal, bituminous coal, to anthracite coal.
•Takes millions of years to convert peat to
anthracite caol.

11. Ranks of Coal
Lignite Subbituminous Bituminous Anthracite
Time of Formation
% C
7000 BTU/lb 9,000 BTU/lb 12,000 BTU/lb 15,000 BTU/lb
Low T, P High T, P
Formation Conditions
Lowest Grade
U.S. Coal
Highest Grade
U.S. Coal

12. Lignite
•Lignite is a relatively young coal deposit
that was not subjected to extreme heat or
pressure.
•Lowest rank of coal with the lowest energy
content.
•Lignite is crumbly and has high moisture
content.
•About eight percent of the coal produced
in the United States
•Mainly found in Western U.S.

13. Subbituminous
•Subbituminous coal typically contains
35-45 percent carbon, compared to 25-35
percent for lignite.
–Thus is has a higher heating value than
lignite.
•Over 40 percent of the coal produced in
the United States is subbituminous.
•Mainly found in Western U.S.
•Used in Central Illinois Coal Burning
Power Plants.

14. Bituminous Coal
•Bituminous coal contains 45-86 percent
carbon, and has two to three times the
heating value of lignite.
•It is the most abundant rank of coal
found in the United States, accounting
for about half of U.S. coal production.
•Bituminous coal has a high Sulfur
content and thus is the Lowest Grade
U.S. coal deposit.
•Illinois Coal!!!

15. Anthracite
•Anthracite contains 86-97 percent carbon and its
heating value is slightly higher than bituminous
coal.
•Highest Grade Coal in U.S.
•Low amount of Sulfur makes this a clean buring
coal.
•Anthracite is very rare in the United States (2% of
overall production).
•The only anthracite mines in the United States are
located in northeastern Pennsylvania.

16. Coal Forming Periods
•Only 2 times in geologic history have the
conditions been just right to form large coal
deposits:
•300 million years ago (Pennsylvanian Period)
–What is now the Eastern and Midwestern United
States was covered by a large marine swamp.
–Low grade Bituminous Coal formed
•60 million years ago (Paleocene Epoch)
–What is now the Montana and Wyoming was covered
by a large freshwater bog.
–High grade Subbitiminous Coal and Lignite Coal
Formed

17. Coal Geology of Illinois
•During Pennsylvanian
Period, the Illinois was
warm and humid,
tropical environment.
•Southern Illinois was
covered by a shallow
sea
•North/central Illinois
was a delta
environment where
rivers from the
northern uplands
drained into swamps
along the coast

18. Coal Formation in Illinois
•The plants that made up
the great delta swamp
forests were buried by the
river and ocean sediment
and compacted through
time to form coal.
•The swamps periodically
covered by marine
sediment deposited by
rising sea level.
•Sulfur from the ocean
water seeped into the peat
buried below, resulting in
low grade coal.

19. Coal Formation in Illinois
•The swamp pants that formed Illinois
coal were not modern trees.
•These plants were similar to modern
weeds with thick exteriors and hollow
interiors.
•The modern ancestors of the coal
forming plants are horsetails which
grow along streams and lake in
Illinois today.
•The main difference is that the coal
plants grew to almost 100 feet high
and had bark 4X as thick as today’s
trees.

20. Coal Grade
•Grade is measure of the amount of
contaminants (“ash”, sulfur and trace
elements) found in the coal.
•Common sources of ash include wind
blown dust, and volcanic ash.
•A low grade coal has a high ash content
(>7%).
•Some of the ash contains trace elements
which are toxic and/or radioactive.

21. Coal Grade
•Seventy-six trace elements are found in coal
•Review the highlighted on the Periodic Table on
the next slide.
–blue, major elements (generally greater than 1.0
percent in abundance)
–red, minor elements (generally greater than or equal to
0.01 percent)
–yellow, trace elements (generally less than 0.001
percent)
•Fifteen elements have been identified as
potentially hazardous air pollutants (HAPs); green
bars in their boxes indicate these fifteen
elements.

22. Coal Grade

23. Coal Grade
•The presence of sulfur also lowers the grade of
the coal.
–Sulfur can end up contributing to smog and acid rain
upon combustion
•Coal that was formed from swamps covered by
sea (salt) water contain high amount of sulfur.
–Common in Eastern U.S. Coals formed during the
Pennsylvanian Period
•Low sulfur coal was formed from freshwater
swamps.
–Common in Western U.S formed during the
Paleocene Epoch.

24. U.S. Coal Production by Rank

25. Major Coal Deposits in the
United States
Eastern
Region
Western
Region

26. Eastern Coal Region
•Annually produces about 48% of total
U.S. coal production.
•Large underground mines and small
surface mines.
•Bituminous (some Anthracite)
•High % Sulfur (Low Grade)
•Highest BTUs of energy

27. Western Coal Region
•Annually produces about 52% of total
U.S. coal production.
•Large surface mines.
–The State of Wyoming (number one coal
state) accounts for over 30% of total U.S.
coal production.
–Largest coal mines in the world.
•Subbituminous (Higher Grade)
•Lower sulfur but fewer BTUs of energy

28. U.S. Coal Production by Location

29. CAA and Coal Production
•The Clean Air Act (CAA) was established
in 1971 to respond to the high levels of air
pollution in the United States.
•CAA regulations required coal burning
power plants to use coal with a lower
sulfur content.
•Production in the western coal region
increased dramatically in 1970’s due the
higher demand for cleaner-burning,
subbituminous coal.

30. Coal Mining
•Mining methods are often
dictated by the type and
location of the coal deposit.
•Coal is mined either by
underground tunneling
(Underground Mining) or by
removing or "stripping" the
covering rocks (Surface or Strip
Mining).
•When the deposit is more than
100 feet below the surface the
underground method is used.
•About 62% of U.S. coal is
produced from surface mines.

31. Coal Mining Methods

32. U.S. Coal Production by
Mining Method
Surface mines
more common
because Western
region Coals are in
demand since the
CAA.

33. Coal Transportation
•After coal is mined and
processed, it is ready to
be shipped to market.
•Coal is shipped by
mainly by train.
•Almost 60 percent of
coal in the U.S. is
transported, for at least
part of its trip to market,
by train.

34. Coal Transportation
•The typical coal train is 100 to 110 cars long-a
mile of coal.
•Each car holds 100 tons of coal which lasts only
20 minutes fueling a power plant.
•One unit train can keep a city of 3,000
households (10,000 people) in electricity for a
year.
•Coal in Wyoming is worth about $5 per ton. By
the time it gets to Illinois, the cost is $30 per ton.
For the user, up to 80% of the cost of the coal
is in the transportation.

35. U.S. Coal Consumption by Sector

36. Uses of Coal
•85% of coal
mined in U.S.
is burned for
electrical
power
generation.
•15% is used in
industrial steel
manufacturing
as Coke.

37. Steel Manufacturing
•Iron occurs in nature as compounds such
as hematite (Fe
2
O
3
) and magnetite
(Fe
3O
4).
•Carbon is used to liberate the iron from
the oxygen.
•Coke is the main source of Carbon used
in steel manufacturing to both liberate iron
and to generate intense heat in a furnace.
Fe
2
O
3
+ C  Fe (Steel) + CO
2

38. COKE
•Coke is produced by
partially burning coal
in a reduced oxygen
atmosphere.
•This removes most
of the gasses leaving
a solid that burns
with a higher
temperature than
coal.
COKE

39. Coal in Illinois
•Coal was first discovered in Illinois more than
300 years ago.
•Coal underlies 37,000 square miles of Illinois
-- about 65 percent of the state's surface.
•Most of the coal is bituminous
•Illinois' coal reserves contain more Btu's than
the oil reserves of Saudi Arabia and Kuwait.
•Illinois coal production peaked in the late
1910s at almost 90 million tons per year.

40. Coal in Illinois

41. Illinois Coal Consumption
•Most of the coal used today in Illinois
comes from Wyoming's Powder River
Basin.
•Compared with that coal, Illinois coal
generally contains more sulfur, which must
be removed from power plant emissions
• The future production of Illinois coal will
depend on mining efficiency relative to the
costs of sulfur removal, among other
factors.

42. Effects of Illinois Coal Mining
•By the late 1970's over 200,000 acres of
land had been affected by surface and
underground mining of coal in Illinois.
•Of this disturbed acreage, over 22,000
acres were identified as being “problem”
acreage.
•This acreage includes
–dangerous mine shafts
–ground subsidence
–acid mine drainage

43. Abandoned
Mine Shafts
•Although most of the tunnel entrances to the
mine shafts in central Illinois have been
sealed, there are a few that are still open.
•Abandoned mines should never be mistaken
for caves. They are very dangerous!!
Sealed Mine Shaft,
West Peoria

44. Examples of
Abandoned
Mine Shafts
in Central Illinois

45. Underground Mine Subsidence
•Mine Subsidence is the sinking or shifting
of the ground surface resulting from
collapse of an underground mine.

46. Sinkhole from Pit Subsidence

47. Cracks from Sag Subsidence

48. Underground Mine Subsidence
•Mine subsidence has been reported in
Pekin, Bartonville and in areas around
West Peoria.
•If you own property in an area of
Illinois where mining once occurred,
you may want to consider insurance
against loss from mine subsidence.
This coverage is available from all
insurance companies licensed in the
State of Illinois.

49. Acid Mine Drainage (AMD)
•Pyrite is commonly present in coal and in the
rock layers overlying the coal.
•Pyrite will react with water and oxygen to form
iron compounds and sulfuric acid.
FeS
2
+ O
2
+ H
2
O  Fe(OH)
3
+ H
2
SO
4
•The products of AMD formation, acidity and
iron, can devastate water and soil resources

50. Water stained from sulfur and
iron compounds

51. Surface Mining Control and
Reclamation Act of 1977
•Set detailed mining and reclamation standards
and regulations for all future coal mining
activities.
•Established an Abandoned Mine Land (AML)
program and fund to address the serious coal
mine problems which were abandoned prior to
August 3, 1977.
•Funding for the reclamation program is provided
by a special production fee on active coal
mining.

52. Coal Mine Reclamation
Outstanding
Examples of
Local Mine
Reclamation
Projects
–Wildlife Prairie
Park (photo
this slide)
–Banner Marsh
and Rice Lake