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CoalI) 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 CoalV) Drawbacks:VI) Mining Coal:VII) Case Study in Ohio

Coal Formation: as heat and pressure increase, various forms of coal are formed; classified by their H2O, C content and heat value; formation occurs from left to right getting harder to right Quality of coal burned and the greatly effects emissions

Coal occurs in well-defined beds that are easy to locate compared to underground oil and gas supplies. Supplies and Uses of Coal

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% of US, ~69% in China, ~90% of 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%

In 2005 US accounted for 22% of global coalconsumption, China 31%.

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Supplies and Uses of Coal

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.

~27% of world’s coal reserves are located in US, 17% Russia, 13% China, 10% India

China’s Energy demands more than tripled in last 35yrs, expects to double in next 15rys

Total global resources estimated to be ~10 million metric tons of coal

Coal accounts for ~95% of US fossil fuel reservesUS burns ~ 1 billion tons of coal/yr

Most Environmentally Impacting Fossil Fuel

Produces more CO2 than oil or gas

Emits Ash and Sulfur & Nitrogen Oxides (SO2 & NOx )

Highly disruptive and scarring to land surface; alters local topography

and habitats.

Causes surface and ground water pollution. ie sediment & inorganic

chemicals

Human health dangers from mining and burning coal

Unreclaimed Surface Mines susceptible to rapid erosion, mass

movement. Deposition occurs in adjacent drainage basins.

Case Study: Gallia County Ohio / Sediment Pollution

Environmental Impacts of Coal Use

Ash: coal use also produces solid waste, 5% to 20% of

original volume

Ash consists of noncombustible silicate minerals and

metals such as Hg, As, Pb, Cr, Cd and Ni causes pollution &

health problems

If captured by scrubbers or confined in combustion

Chambers, it still has to be disposed of

A single coal-fired electric power plant can produce

>1,000,000 tons of solid waste each year; most is put into

landfills

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Environmental Impacts of Coal Use

• Sulfur (S)– S content of coal can be > 3%; sulfur gases (SO2) are produced

when coal is burned and mined. Spoil Banks contain sulfur which reacts with water and air to produce sulfuric acid--polluting streams, lakes and ground water.

“Acid Mine Runoff”

– Acid Deposition

• 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

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

this decade.

Due to dangers and expenseof subsurface coal mining,surface mining nowdominates coal extraction

Coal Mining Accidents443 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.

2008: 3,215 deaths

Source: State Administration of Work Safety

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.

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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

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.

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184 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 Pollution2.2ft/25yrs, 27mm/yr or27,000mm/1,000yrsE. Slough: 1-3mm/yr

The dark red area is where strip mines have been reclaimed in SE Ohio

Muskingum Mine Reclamation in SE Ohio

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Before and after Open Surface Mine reclamation in eastern Tennessee. Photo on left shows a contour mine where they followed

a coal seem and left spoil on the lower hillside.

Clean Coal Technology(pg 286)

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 FloridaCosts 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 10yrs in the US will have IGCC. Japan currently has 18 IGCCplants

IGCC Important Nonrenewable Energy Sources

Oil drillingplatformon legs

Mined coal

Pipeline

Pump

Oil well

Gas well

Oil storage

CoalOil and Natural Gas Geothermal EnergyHot waterstorage

Contourstrip mining

PipelineDrillingtower

Magma

Hot rock

Natural gasOil

Impervious rock

Water Water

Floating oil drillingplatform

Valves

Undergroundcoal mine

Water is heatedand brought upas dry steam or

wet steam

Waterpenetratesdownthroughtherock

Area stripmining

Geothermalpower plant

Coal seam

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Environmental Effects of Extracting ResourcesEnvironmental Effects of Extracting Resources

Steps Environmental Effects

exploration, extraction

MiningDisturbed land; mining accidents;health hazards; mine wastedumping; oil spills and blowouts;noise;ugliness; heat

Solid wastes; radioactive material;air, water, and soil pollution;

noise; safety and healthhazards; ugliness; heat

Processing

transportation, purification,manufacturing

Use

transportation or transmissionto individual user,

eventual use, and discarding

Noise;thermal water pollution;

pollution of air, water, and soil;solid and radioactive wastes;

safety and health hazards; heat

Study Questions/Key Conceptsabout 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 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?

• Types of Nuclear Change: fusion, radioactivity & ……….

Nuclear Energy

fusion

radioactivity

Fission fragment

Fission fragment

Energy

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Uranium-235nucleus

Unstablenucleus

Nuclear Fission

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U23592

9236 Kr

Ba14156

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9236 Kr

U23592

U23592

Ba14156

9236

Kr

Ba14156

9236

Kr

Ba14156

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Nuclear Energy

• Advantages of Nuclear Fission:less air pollutants and CO2 emissions than burning fossils fuels. less water pollutionless land disruption, ~1/10 as much as surface mining.

• Concerns: Although nuclear power plant accidents can cause major catastrophes (e.g. Chernobyl), several other concerns are:– disposing of low-level and high-level radioactive waste– maintaining degrading power plants– high maintenance, high cost to decommission– produces weapons grade materials– U235 makes up only ~ 0.7% of all natural Uranium

Where does Uranium come from?• U is a relatively uncommon element in Earth’s crust but it can

become concentrated by certain geologic processes– In the late stages of cooling granitic magma slowly underground U found

in the mineral Uraninite (UO2) which is highly soluble, also known as Pitchblende

– Uraninite passes into solution as granite is weathered.Then it is transported by groundwater into permeable sediments and sedimentary rocks

– It tends to bond to the surfaces of organic matter and also may combine with K & V to become Carnotite K2(UO2)2(VO4)2·3H2O

– U is then mined from ancient streambeds, it’s encrusted around sand and gravel grains. Formed into cylindrical pellets ~1.5cm long and 8.5grams.

– Energy in 1 pellet is equal to 1 ton of coal

• In North America– ~200 m.y.o. stream gravels in CO, NM, WY, TX often associated

with fossilized plant and wood remains

Concerns continued…

• U235 is the only naturally occurring isotope that can maintain a nuclear chain reaction. It makes up ~ 0.7% of all natural U, and it is consumed during fission. Global Uranium reserves is ~ 6 million tons. Existing plants use ~77,000 tons/yr

• At the current rate of use, it’s estimated that recoverable reserves of U235 may be sufficient to run nuclear power plants for only another ~80 years with no reduction of our dependence on fossil fuels.

• Non-fissionable U238 makes up the remaining 99.3%. Scientists are working on ways to safely and economically produce fissionable Pu239 from the U238.

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More Nuclear Energy

• If we built very quickly enough nuclear power plants to replace all fossil fuel usage, global Uranium consumption would be ~1,3 million tons/yr. At that rate, reserves would last ~ 5 years.

• An overnight conversion from fossil fuels to nuclear energy is not going to happen.

• Breeder Nuclear Fission Reactors• http://www.wired.com/wired/archive/12.09/china.html

http://www.yuccamountain.org/

Dealing with Nuclear Waste?

Low-level wasteHigh-level waste

- Underground burial - Disposal in space - Burial in ice sheets - Dumping into

subduction zones- Burial in ocean mud - Conversion into

harmless materials

Low-level wasteHigh-level waste

- Underground burial - Disposal in space - Burial in ice sheets - Dumping into

subduction zones- Burial in ocean mud - Conversion into

harmless materials

Clay bottom

Up to 60deep trenchesdug into clay.

As many as 20flatbed trucksdeliver wastecontainers daily.

Barrels are Stacked andsurroundedwith sand.Coveringis moundedto aidrain runoff.

Disposing of Nuclear Waste• Low-level radioactive wastes from nuclear power plants, hospitals, universities

and industry:– give off small amounts of radiation for 100 - 500 years

– until 1970s these wastes were put into steel drums and dumped into the ocean

– except for UK and Pakistan, such waste is put into special landfills run by gov’t

– construction of new dumping sites--highly controversial--NIMBY

• High-level radioactive wastes from spent reactor fuel rods and nuclear weapons production:– give off large amounts of radiation for a short time and then low-level amounts for 1000s

of years -->must be stored for 1000s of years to 240,000 years

– no plan yet is scientifically and economically practical

• Bury it deep underground on land or ocean floor--can we be sure of geologic processes at any site that far into the future? Leakage onto surface of sea floor?

• Shoot it into space--high cost and high risk

• Bury it under Antarctic or Greenland ice sheets--stability of ice sheets?

• Dump into subduction zones--wastes brought to surface by volcanic activity, leakage before subduction occurs

• Change to less harmful isotopes--high cost, technology not yet developed, still produces low-level radioactive waste

Nuclear Waste approximate Locations

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More Nuclear Energy

• Nuclear power plants were 1st developed in the late 1950’s. It was predicted then that by the year 2000, 1800 power plants would supply 21% of the world’s commercial energy and most of the world’s electricity.

• >50 years of R & D, > 2 trillion $’s spent, in 2008 ~439 nuclear reactors in 30 countries produce ~ 6% of the world’s commercial energy and 16% of the world’s electricity. US has 104 operating plants that provide ~21% of electricity in 2008

Study Questions/Key Conceptsabout Nuclear Energy

1. What are the 3 types of Nuclear Change?

2. What is Nuclear Fusion and where is this taking place?

3. What is nuclear fission, how does it work, what elements are used? How is the energy used to produce electricity?

4. Where does Uranium come from?

5. What is the difference between U235 and U238?

6. What is Uraninite and Carnotite

7. What types of waste are generated from Nuclear Energy?

8. What are some ideas for dealing with nuclear waste disposal, advantages /disadvantages?

9. What is a Breeder Nuclear Power Plant?