ES 10
Methane Clathrates
Nonrenewable Energy Resources Part III
Gas Hydrates and COAL
aka Methane Hydrates or Gas Hydrates
another source of “unconventional” fossil fuels
Past to Present (31 slides)
What are fossil fuels
Why use Oil / Natural Gas
Drawbacks
Where does oil come from?
Oil Traps; Source, Reservoir & Cap Rocks
Abiotic Oil?
Who has the oil & how much is there? How long will it last?
Where does US get it’s oil?
Unconventional sources of oil and gas: Oil Shale, Tar Sands,
Methane Clathrates, aka Methane Hydrates, Gas Hydrates
Newer Estimates: (2013)
~500 – 2,500
Approx 2 – 10 X
the amount of
conventional
natural gas
Methane Hydrate recovered from Blake Ridge
Stored mostly in broad, shallow layers beneath the seafloor, methane hydrate is, by some
estimates, twice as abundant as all other fossil fuels combined. The yellow squares show
where methane hydrate has already been recovered; the blue dots, where it is thought to exist.
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Estimated ~1,300 trillion cubic ft off N and S Carolina,
>60X amount US uses each year (~20 trillion cubic ft/yr)
Estimated total US gas Hydrate deposits ~320,222 trillion cubic ft,
at 10% recovery, enough to last 1600 years
Seismic Reflection Profile data on Blake Ridge showing BSR
(meters below sea level on left, meters below ocean floor on right)
P-Wave rates in hydrates
can be as fast as
3.0 – 3.6Km/s
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Nonrenewable Energy Resources
Part II
Coal
Coal
I) Coal definition: a biochemical, nonclastic sedimentary
rock rich in C, minor S, N, H, metals, silicates
II) Formation of Coal: forms from highly compressed remains of land
plants; tropical swampy setting lush plant growth bacterial decay burial in
anaerobic (low oxygen) conditions buried plant remains exposed to increased
pressure & heat over millions of years forming a variety of coal.
Earth’s most abundant fossil fuel. Most coal formed in
carboniferous period ~ 360 - 286 my BP
Land plants appear ~ 400 my BP
III) Types of Coal:
IV) Supplies and Uses of Coal
V) Drawbacks:
VI) Mining Coal:
VII) Case Study in Ohio
Coal Formation: as heat and pressure increase, various forms of coal
are formed. Coal is classified by H2O & C content & heat value;
formation occurs from left to right getting harder to the right.
Quality of coal burned greatly effects emissions.
Coal occurs in well-defined beds that are easy to locate
compared to underground oil and gas supplies.
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Supplies and Uses of Coal
Total global resources estimated to be ~948 billion
tons of coal = to ~ 4.2 billion barrels of oil
Source: En Information Administration
Identified & unidentified reserves could last world for 214 1,125 years (US will last for ~234 years, at current production)
Burning coal generates: 62% of world’s electricity,
(~51% in US, ~69% in China, ~90% in Poland and
South Africa) and 75% of world’s steel
Using coal to make electricity accounts for ~1/3 of U.S. carbon
emissions, China, India, Australia, Greece and Czech Rep. >70%
(33% - >70% C emissions)
Supplies and Uses of Coal
~27% of world’s coal reserves are located in US, 17%
Russia, 13% China, 10% India.
In 2011 US coal exports topped 107 mill tons worth
$16Billion, most since 1991, more than doubled since
2006, mostly to Asia.
China opens a new large coal burning plant every
~10 days, has reserves for ~300yrs at current usage
rate, plans to triple capacity by 2020.
China’s Energy demands more than tripled in last 35yrs.
http://waterdefense.org/content/coal
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Coal accounts for ~95% of US fossil fuel reserves
US burns ~ 1 billion tons of coal/yr
Environmental Impacts of Coal Use
Most Environmentally Impacting Fossil Fuel
Sulfur (S)
Produces more CO2 than oil or gas, contributes to more climate change
than any other fossil fuel
Emits Sulfur & Nitrogen Oxides (SO2 & NOx ) = forms acids
Shows up in spoil banks, rivers, acid deposition, Sulfur can be >3%
– S content of coal can be > 3%; Spoil Banks contain sulfur which
reacts with water and air to produce sulfuric acid--polluting streams,
lakes and ground water. (Sulfur on the ground)
“Acid Mine Runoff”
–
Highly disruptive to land surface; alters local topography and habitats.
Causes surface and ground water pollution.
Human health dangers from mining & burning coal; respiratory diseases
Environmental Impacts of Coal Use
Ash / Solid Waste: 5% to 20% of original volume, consists of
noncombustible silicate minerals and metals such as Hg, As, Pb,
Cr, Cd and Ni causes pollution & health problems.
A single coal-fired electric power plant can produce > million
tons/year; most is put into landfills
Acid Deposition sulfur gases (SO2) are produced when coal is
burned and mined. (Sulfur gases in the atmosphere)
• gases are poisonous and extremely irritating to eyes and lungs
• can harm fish and aquatic life in streams and lakes
• acidify soil and stunt plant growth
• dissolve rock--corrosion of monuments
• Ocean acidification
How is coal extracted?
A. Subsurface Mining:
•
•
•
•
•
•
dangerous and expensive
mine collapse
miners contract Black
Lung Disease
increased cancer risks
explosions of natural gas
in mines
>47,700 deaths in China
in last 10 years.
Unreclaimed Surface Mines susceptible to rapid erosion, mass
movement. Sediment deposition occurs in adjacent drainage basins.
Case Study: Gallia County Ohio / Sediment Pollution (later)
Due to dangers and expense of subsurface coal mining,
surface mining now dominates coal extraction
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Coal Mining Accidents
443 deaths in US between 1996 – 9/24/09
China’s coal mining deaths in recent years:
2000: 5,300 deaths.
2001: 5,670 deaths.
2002: 5,791 deaths. There are 50X as many coal miners
2003: 7,200 deaths.
in China compared to the US.
2004: 6,027 deaths.
2005: 5,986 deaths.
2006: 4,746 deaths.
2007: 3,786 deaths.
Source: State Administration of Work Safety
2008: 3,215 deaths
2012: 1,384 deaths
How is coal extracted?
B. Surface Mining: far less dangerous and cheaper but causes
many more environmental problems, accounts for ~60% of all coal
mining.
1. Open Pit: ie. Similar to Bingham Copper Mine in Utah
2. Strip Mining:
a. Area Strip Mining ie. In southeastern Ohio, relatively flat terrain, large areas
b. Contour Strip Mining used in very hilly areas.
3. Mountain Top Removal Mining (MTR or MTM): explosives
used to blast away tops of mountains, in some cases >1,000ft, then large excavators
remove the coal. Most common in Appalachian Mountains.
Bagger 293 is a giant Bucket Wheel Excavator, used in Germany.
It’s 315ft tall, 13,500 tons, requires 5 people to operate. One of the
largest terrestrial vehicles in the world.
Mountain Top mining in West Virginia, 2003
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Ridge top debris (often containing selenium, arsenic, coal and
sulfur) is typically dumped into adjacent river valleys.
~560 miles of streams have been buried in West Virginia.
The Office of Surface Mining Reclamation And Enforcement
(OSM) was created in 1977
Locations of US Abandoned Mine Land (AML) problems that are
eligible for OSM funding.
MTR 8 min
moviehttp://www.youtube.com/watch?v=RPixjCneseE
184 Ohio Coal Mines: 84 have been reclaimed, there is
funding for 9 more & 91 are unfunded
(no work done as of 2008)
Grey areas are strip mines
that have not been
reclaimed in SE Ohio
Case Study: Gallia County
Ohio
Sediment Pollution
2.2ft/25yrs, 27mm/yr or
27,000mm/1,000yrs
E. Slough: 1-3mm/yr
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The dark red area is where strip mines
have been reclaimed in SE Ohio
Muskingum Mine Reclamation in SE Ohio
Forest and Grassland
Muskingum Mine Reclamation in SE Ohio
Before and after Open Surface Mine reclamation in eastern
Tennessee. Photo on left shows a contour mine where they followed a
coal seem. Spoil is on the lower hillside.
Clean Coal Technology
IGCC
A variety of processes designed to reduce environmental impacts of burning coal
• Washing minerals / impurities from the coal,
• Carbon capture: capture and store C02 and other
pollutants
• Sulfur Dioxide removal
• IGCC (Integrated Gasification Combined Cycle):
Converts coal/water slurry into gas (mostly H and C02) and
removes impurities. Only 2 in US as of 2007: Terre Haute Indiana
and Tampa Florida
(Mississippi plant under construction)
Costs 15 – 20% more to build than conventional design, but they’re
~15% more efficient than normal coal fired plants .
Currently only 12% of 80 new coal plants planned in the next 10
yrs in the US will have IGCC. Japan currently has 18 IGCC plants
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Important Nonrenewable Energy Sources
Environmental Effects of Extracting Resources
Steps
Oil and Natural Gas
Floating oil drilling
platform
Oil drilling
platform
on legs
Oil storage
Oil well
Gas well
Valves
Pipeline
Pump
Impervious rock
Natural gas
Oil
Water
Coal
Geothermal Energy
Hot water
Contour
storage
strip mining
Geothermal
power plant
Area strip
Pipeline
mining
Drilling
Mined coal
tower
Water
penetrates
Underground
down
coal mine
Water is heated
through
and brought up
the
as dry steam or
rock
wet steam
Coal seam
Hot rock
Water
Magma
Mining
exploration, extraction
Processing
transportation, purification,
manufacturing
Use
transportation or transmission
to individual user,
eventual use, and discarding
Environmental Effects
Disturbed land; mining accidents;
health hazards; mine waste
dumping; oil spills and blowouts;
noise;
ugliness; heat
Solid wastes; radioactive material;
air, water, and soil pollution;
noise; safety and health
hazards; ugliness; heat
Noise;
thermal water pollution;
pollution of air, water, and soil;
solid and radioactive wastes;
safety and health hazards; heat
Study Questions/Key Concepts about Coal
1. Describe the shifts in commercial energy resource use in the US
since the 1800s
2. What is Coal and how does it form? What are the different
types?
3. What are the main advantages and disadvantages of using coal?
4. Where and when did coal deposits form? Other than H and C
what other elements naturally occur in coal?
5. How is coal extracted/mined and what are the differences?
6. List and explain several of the environmental impacts of
mining, processing and using coal.
7. What does OSM stand for? What is the mission?
8. Describe some of the environmental drawbacks of surface
mining that has occurred in south eastern Ohio.
9. What is Clean Coal Technology?
https://www.youtube.com/watch?v=cJ-J91SwP8w
(“300 Years of FOSSIL FUELS in 300 Seconds”)
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