5.0 Fuels: Coal

Frank R. Leslie, B. S. E. E., M. S. Space Technology, LS IEEE

1/25/2010, Rev. 2.1.0

fleslie @fit.edu; (321) 674-7377

www.fit.edu/~fleslie

In memory of the perished miners of Sago and Melville, West VirginiaJanuary, 2006

In Other News . . .

Tax credit for wind turbines at $1000/kW up to $4000/kW as part of bailout package [http://www.kfsm.com/Global/story.asp?S=9729594]

Auto CAFÉ standards: Obama directs EPA to assess individual states adopting CA standards

“Clean Coal” still funded at a demonstration site in IL

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Overview

Romans in England used coal about 100 - 200 A.D. http://www.fe.doe.gov/education/energylessons/coal/coal_history.html

Previously, only wood and peat were burnedCoal is the predominant fuel, but is not renewableWe are consuming fuel that took millions of years

to formChina loses some 50k to 60k miners a year! Jevon’s Paradox states that conservation of a fuel

(say coal) will increase its consumption as it becomes cheaperPrice will fall, and longer-term demand increases

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5.0 About This Presentation

5.1 History5.2 Fuel Sources and Preparation5.3 Coal Transportation5.4 Energy Content5.5 Estimated Reserves5.6 Coal Usage5.7 Coal Combustion and Gasification5 Conclusion

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5.1 History

Romans used coal some 2000 years ago The US Hopi Indians burned coal about 1300

B.C.E. Explorers “discovered” US coal in 1673 The English used coal ~1700 as it burned hotter

and cleaner than charcoal In 1740s, coal mines were started in Virginia In 1785, coal coke replaced charcoal for steel-

making In 1820, the Baltimore & Ohio (B&O) Railroad and

the Chesapeake & Ohio (C&O) Canal began moving coal

In 1880s, electricity was generated using coal and steam stationary engines at Edison’s Pearl Street Station in Manhattan

(But first hydroelectric plant at Appleton WI 1882)

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Ref.: http://www.fe.doe.gov/education/coal_history.html

                                                                                

Wikipedia.com

5.1.1 Energy Consumption Relations

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Consumption is a indicator of affluence, or possibly just cheap available energy

If you use as much energy as possible, you will achieve a very high annual income! (or could that be backwards?! Correlation?)

5.2 Sources and Fuel Preparation

Coal is obtained byDeep-mining

Tunneling to follow a surface seam

Boring to penetrate surface burden to reach it

Strip-miningRemoving the surface

burden of soilExcavating the coalReplacing the surface

burden to make a lake or park

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http://www.archcoal.com/environment/reclamation.asp

5.2.1 US Coal Regions

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5.2.2 Fossil Fuels are Limited

030126 Ref.: National Energy Technology Lab. Why Combustion? CD_ROM

5.2.3 Underground mining is hazardous

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Ref.: http://www.fe.doe.gov/education/coal_mining.html

                                                                                                      

Cave-ins and explosion of methane cause ~33 US deaths (2007) and many injuries each year

“Long-wall” mining can produce coal quickly and inexpensivelyPillars left to hold

up the roof Is all the cost of

mining death, injury, and disease in the price of coal?

http://www.msnbc.msn.com/Default.aspx?id=3863126&p1=01%7C%7C%7C%7C003

5.2.4 Strip Mining at Consol Coal

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5.2.5 Mining productivity increased by machines

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5.3 Coal Transportation

Classically, trains move coal from the mine to the point of use

Now, coal is often burned in mine-head power plants and is carried directly there from the mine to the boiler pile by conveyor belts

Ships also move coal in ~50,000 ton amounts

Pipelines are used to move an Orimulsion coal slurry (mixed with water) to the end, where water separation occursIs the water clean? Where

does it go?100125

5.3.1 Coal Transportation Prices

Cl

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5.4 Energy Content and Selection

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Peat, dried 8 430 Btu/lb

Lignite 12 070 Btu/lb

Bituminous Coal 14 480 Btu/lb

Coal, General 15 000 Btu/lb

Anthracite Coal 15 550 Btu/lb

Ref.: Zerban and Nye, 1952

What’s wanted is heat, so the Btu/$ is more useful

5.4 Energy Price per Million Btus

Coal is cheapest, then natural gas, and fuel oil is highest

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5.5 Estimated Reserves and How They are Estimated

In 1955, reserves of coal and lignite were estimated at 3000 billion tons

US coal consumption was then 500 million tons per year It would then last 3000 billion/500 million = 6,000 years So what’s the problem? In 2004, US recoverable reserves were estimated at

267,312 million short tons In 2004, US consumption was 1112 million short tons, or

240 years remaining! The cost increases as coal becomes more difficult to mine,

so consumption may decrease, extending the time remaining

Economic recovery of coal limits the possible amount that can be mined (if more energy is required to mine the coal than can be gotten from that coal, it’s not worth it! EROEI: energy return on energy investment)

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5.6 Coal provided 54% of US electricity in 2002

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5.6.1 Coal Predominates in Electricity Generation

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5.6.2 Coal Advantages and Disadvantages

Coal is cheap and is estimated to last another 100 - 400 years (depending upon who estimates)Reserves/consumption = years to goRising price in between will decrease consumptionRemaining coal will last longer

Coal firing has produced excessive pollution in the past but is now cleaner

“Clean Coal” technologies clean the coal to remove sulfur, remove stack fly ash, and process the fumes to remove 95% of NOx and ~80% of mercury

Coal requires processing to wash some sulfur out before burning it [Where do we put the wash water?]

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5.6.3 Coal Pollution is Decreasing

060115http://www.netl.doe.gov/publications/proceedings/02/CBUniversity/bonk-ctuaw91202.pdf

5.6.4 Gasification Combined Cycle

050118http://www.netl.doe.gov/publications/proceedings/02/CBUniversity/bonk-ctuaw91202.pdf

5.7.1 Oxygen fires the boiler without N2 present

040120http://www.netl.doe.gov/publications/proceedings/02/CBUniversity/bonk-ctuaw91202.pdf

5.7.2 Coal Gasification

If oxygen is separated out of the air, it can be used to partially combust the coal to produce a burnable gas

When oxygen is used instead of air (contains nitrogen), NO2 cannot be formed

Outputs are high pressure steam and “syngas”

There is some residual slag that can be buried or used in roadbed construction

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http://www.netl.doe.gov/publications/proceedings/02/CBUniversity/bonk-ctuaw91202.pdf

5 Conclusion

Coal will last ~a hundred years longer than oil or NG or nuclear (uranium ore is depletable too)

Coal will continue to be a primary fuel close to coal mines

Coal is most suited to fixed energy plants; while mobile use requires oil, gasoline, or natural gas

Coal is relatively cheap, so we use a lot of itCombustion requires antipollution processing, and

sequestration is being developed to capture CO2 Coal may be the replacement for oil, since synoil

can be madeSome people don’t want cleaner coal energy since

more coal would be mined

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References: Books

Zerban, Alexander H. and Edwin P. Nye. Power Plants. Scranton: International Textbook Co., 1952.

Brower, Michael. Cool Energy. Cambridge MA: The MIT Press, 1992. 0-262-02349-0, TJ807.9.U6B76, 333.79’4’0973.

Duffie, John and William A. Beckman. Solar Engineering of Thermal Processes. NY: John Wiley & Sons, Inc., 920 pp., 1991

Sørensen, Bent. Renewable Energy, Second Edition. San Diego: Academic Press, 2000, 911 pp. ISBN 0-12-656152-4.

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References: Websites, etc.

15-CT-005-29 Why Combustion? http://www.netl.doe.gov/coalpower/combustionhttp://www.google.com/search?q=coal+history&hl=en&lr=&ie=UTF-8&oe=UTF-8 searchRef.: National Energy Technology Lab. “Why Combustion?” CD_ROMhttp://www.cmhrc.pwp.blueyonder.co.uk/ Coal history sitehttp://www.fe.doe.gov/education/coal_history.html DOED:\TOPICAL\topical21.pdf http://www.tva.com/________________________________________________________________________________www.dieoff.org. Site devoted to the decline of energy and effects upon populationwww.ferc.gov/ Federal Energy Regulatory Commissionwww.google.com/search?q=%22renewable+energy+course%22solstice.crest.org/dataweb.usbr.gov/html/powerplant_selection.html

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Olin Engineering Complex 4.7 kW Solar PV Roof Array

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Questions?

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