1. Clean Coal Technology Sam Harris http://i.treehugger.com/images/2007/5/24/coal%20chunks.j pg

2. Overview ● Burning and current use of Coal ● “Clean” coal technologies ● Is “clean” coal actually clean? ● The future of clean coal and politics ● Summary

3. Types of Coal – Lignite (brown coal) - 25% to 35% carbon, around 70% when dry – Subbituminous – 35% to 45% carbon – Bituminous – 45% to 86% carbon – Anthracite (black coal) – 86% to 98% carbon

4. Coal and Electricity ● There are about 600 U.S. coal plants. ● Coal generates 54% of our electricity ● There are 249 projected coal power plants to be built between 1999 and 2009, another 483 by 2019, and another 710 by 2030

5. Burning of Coal ● In 2002 fossil fuels released 23 billion tons of CO2 into the atmosphere ● of the 23 billion tons 41% was from coal ● Burn 1 ton of black coal and you get 4 tons of CO2 ● Anthracite releases 67% more CO2 than methane and brown coal releases 130% more CO2 emissions than methane ● Coal also contains trace amounts of sulfur and Nitrogen that when burned can cause environmental issues

6. The Effects of Sulfur Dioxide from Coal ● In the 1960s trees as well as aquatic life in lakes were dying ● Due to acid rain from sulfur dioxide emissions from burning of coal ● Created “scrubbers” to clean the coal ● The sulphates had reflected light back into space keeping the earth cooler ● Once the sulphates were gone the temperature of the earth rose

7. Why is coal still used? ● Cheapest for power stations relative to the amount of heat it generates when burnt http://www.economist.com/business/displaystory.cfm?story_id=101454 92

8. How does a coal power plant work? http://www.cs.wright.edu/~egr190/Alternative%20energy/coalart. gif

9. http://upload.wikimedia.org/wikipedia/commons/d/d6/Coal_power_plant_ Datteln_2_Crop1.png

10. So what is clean coal? ● It is actually a vague term that does not describe any one process ● Can include the removal of nitrogen and sulfur that create acid rain ● Can include the storage of CO2 ● The term “clean coal” is abused

11. “Clean” Coal Technologies ● Coal washing ● Wet scrubbers ● Low NOx burners ● Electrostatic precipitators ● Gasification ● Carbon Capture and Storage (CCS) ● Fuel Cells ● Magnetohydrodynamics

12. Coal Washing ● Grinding coal into pieces and passing it through gravity filtration ● One technique: Putting coal into a barrel with a liquid with a specific density where the coal floats and the impurities sink http://news.bbc.co.uk/1/hi/sci/tech/4468076.stm

13. Wet Scrubbers ● When the emissions reach the flue of the furnace limestone and water are sprayed ● The SO2 reacts with the calcium carbonate (limestone) to form gypsum (calcium sulfate) ● The gypsum is collected and used for construction ● 99% effective http://news.bbc.co.uk/1/hi/sci/tech/4468076.st m

14. Nitrogen Oxides (NOx) ● Use of ● First stage: combustion occurs in an oxygen deficient zone where NOx is usually formed ● Second Stage: hydrocarbons are formed which react with the already formed NOx ● Third Stage - internal air staging completes the combustion but may result in additional NOx formation, which can be minimized by completing the combustion in an air lean environment

15. Electrostatic Precipitators (Particle emissions) ● Creates an electrical field that removes unwanted charged particles ● 99% effective http://news.bbc.co.uk/1/hi/sci/tech/4468076.st m

16. Gasification ● Coal is reacted with oxygen and steam to form a “syngas” (mostly hydrogen and part CO) ● Syngas is cleaned and burned which then turns a turbine ● As gas cools it heats water, which turns another turbine

17. http://news.bbc.co.uk/1/hi/sci/tech/4468076.st m

18. Gasification (continued) ● Gasification is seen as part of zero-emission system ● Improved SO2 and NOx emissions (already low) ● Unproven on widespread scale ● Up to 45% efficient ● Currently only demonstration units exist on a trial basis ● Right now syngas being cleaned at low temperatures. In the future will be cleaned at higher temperatures, increasing efficiency ● Costly, but current coal power plants can be modified

19. Carbon Capture and Storage (CCS) ● Capturing CO2 and storing it underground (geosequestration) http://news.bbc.co.uk/1/hi/sci/tech/4468076.st m

20. CSS (continued) ● There are many problems with CSS ● CO2 is hard to capture ● Once captured it needs to liquified which takes 20% of the energy yielded from the coal ● Where the CO2 is stored needs to be monitored ● There are only so many places that are good for mass storage ● Transportation could be costly

21. Fuel Cells ● Allow hydrogen from coal to react with oxygen to produce electricity electrochemically ● Still in early development ● Costly http://www.australiancoal.com.au/cleantech.htm#fuelc ell

22. Magnetohydrodynamics ● Coal is burned to form an extremely hot gas or plasma ● Given electrical charge by adding a compound like potassium salt ● The charged gas or plasma is passed through a magnetic field and electricity is produced ● The heat from the combustion gases is used to turn a steam turbine too ● Still in development ● Costly

23. So is “clean” coal really clean? ● Unfortunately there is no way to make coal clean ● Processes like gasification can make coal burning more efficient, but it still burns plenty of CO2 ● CO2 can be stored underground using CSS, but that could lead to more problems in the future ● Best solution: STOP USING COAL!!!!

24. “Clean” Coal and Politics ● Barack Obama has said that he would develop five first-of-their-kind coal-fired plants with CCS technology ● Wants to spend $150 billion over 10 years for renewable energy sources such as wind, solar, biofuels, plug-in hybrids and clean-coal technology ● Wants to cut carbon-dioxide emissions from power plants, oil companies and other industries. ● But we're talking politics.

25. Summary ● Coal is very inefficient and is a huge cause of global warming, but cheap ● Clean coal is a term that describes many different technologies ● Clean coal is by no means clean ● CSS will be put in use in the near future, which may or may not be a good thing

26. Works Cited ● "Clean Coal Technologies - Examples." Australian Coal Association. Australian ● Clean coal technology: How it works." BBC News. 28 Nov. 2005. BBC News. 6 ● "Coal power Still going strong." The Economist 15 Nov. 2007. ● Davidson, Paul. "Major issues await Obama." USA Today 6 Nov. 2008. ● Flannery T. 2005. The Weather Makers: How Man is Changing the Climate and ● "IEA Clean Coal Centre." IEA Clean Coal Centre. IEA Clean Coal Centre. 6 Nov. ● Schirber, Michael. "What Exactly Is Clean Coal?" Foxnews.com. 3 Nov. 2008. Fox