coal

1. CoalCoal

2. COALCOAL
 Coal is a solid fossil fuel that is formed inCoal is a solid fossil fuel that is formed in
several stages as the buried remains of landseveral stages as the buried remains of land
plants that lived 300-400 million years ago –plants that lived 300-400 million years ago –
subjected to heat and pressuresubjected to heat and pressure

3. COALCOAL
 Mostly carbonMostly carbon
 Some sulfur – forms sulfur dioxide (SOSome sulfur – forms sulfur dioxide (SO22 ––
acid deposition)acid deposition)
 Some mercury and radioactive materialsSome mercury and radioactive materials

4. Fig. 16-13, p. 369
Waste heat
Coal bunker Turbine
Cooling tower
transfers waste
heat to
atmosphere
Generator
Cooling loop
Stack
Pulverizing
mill
Condenser Filter
Boiler
Toxic ash disposal

5. COALCOAL
 World’s most abundant fossil fuelWorld’s most abundant fossil fuel
 Generates 45% of world’s electricity, 53% ofGenerates 45% of world’s electricity, 53% of
U.S. electricity (1997), 37% (2012), 73% ofU.S. electricity (1997), 37% (2012), 73% of
China’s fuel consumption (also declining)China’s fuel consumption (also declining)
 Coal reserves in U.S., Russia and ChinaCoal reserves in U.S., Russia and China
could last hundreds to > a thousand yearscould last hundreds to > a thousand years

6. COALCOAL

7. COALCOAL

8. PROBLEMS WITH COALPROBLEMS WITH COAL
 Dirtiest fossil fuelDirtiest fossil fuel
 Fine particles –Fine particles – sootsoot
 MercuryMercury
 Sulfur dioxide (SOSulfur dioxide (SO22) – acid deposition,) – acid deposition,
 COCO22 from combustion - GHGfrom combustion - GHG
 Trace amounts of radioactive materialsTrace amounts of radioactive materials
 Toxic ash – landfills, mines, slurry in holdingToxic ash – landfills, mines, slurry in holding
pondsponds

9. PROBLEMS WITH COALPROBLEMS WITH COAL
Coal sludge pond in West VirginiaCoal sludge pond in West Virginia

10. COALCOAL
 Dangerous – accidents, black lung diseaseDangerous – accidents, black lung disease

11. How Do They Do It –
Coal Mining

12. COALCOAL
 Coal is the mostCoal is the most
abundant fossil fuel,abundant fossil fuel,
but compared to oilbut compared to oil
and natural gas it isand natural gas it is
not as versatile, hasnot as versatile, has
a high environmentala high environmental
impact and releasesimpact and releases
much more COmuch more CO22 intointo
the tropospherethe troposphere

13. CLEAN COALCLEAN COAL
 Clean coal technologyClean coal technology – using a variety of– using a variety of
techniques to mitigate COtechniques to mitigate CO22 and other GHGand other GHG
emissions from burning coalemissions from burning coal

Ex: air pollution control at power plantsEx: air pollution control at power plants

14. CLEAN COALCLEAN COAL
 Funded by coal and electric utility industriesFunded by coal and electric utility industries
 Environmentalists think it’s an oxymoronEnvironmentalists think it’s an oxymoron
 What about:What about:

Hazardous coal ash, mining, other pollutionHazardous coal ash, mining, other pollution
 What happens to energy yield?What happens to energy yield?
 Harmful and environmental effects notHarmful and environmental effects not
included in cost – not full cost pricingincluded in cost – not full cost pricing

15. Clean Coal Technology

16. Synfuels from CoalSynfuels from Coal
 Coal can be converted intoCoal can be converted into syntheticsynthetic
natural gasnatural gas (SNG or(SNG or syngassyngas) by) by coalcoal
gasificationgasification and liquid fuels (such asand liquid fuels (such as
methanol or synthetic gasoline) bymethanol or synthetic gasoline) by coalcoal
liquefactionliquefaction - burn cleaner than coal- burn cleaner than coal

ExpensiveExpensive
 Burning them adds more COBurning them adds more CO22 to the troposphereto the troposphere
than burning coal = lower net energy yieldthan burning coal = lower net energy yield

Uses lots of waterUses lots of water

17. Synfuels from CoalSynfuels from Coal