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Lignite



  Lignite, often referred to as brown coal, is the lowest rank of coal and used almost exclusively as fuel for steam-electric power generation. It is brownish-black and has a high inherent moisture content, sometimes as high as 66 percent, and very high ash content compared with bituminous coal. It is also a heterogeneous mixture of compounds for which no single structural formula will suffice.

The heat content of lignite ranges from 10 to 20 MJ/kg (9 to 17 million Btu per short ton) on a moist, mineral-matter-free basis. The heat content of lignite consumed in the United States averages 13 million Btu/ton (15 MJ/kg), on the as-received basis (i.e., containing both inherent moisture and mineral matter). When reacted with quaternary amine, amine treated lignite (ATL) forms. ATL is used in drilling mud to reduce fluid loss.

Because of its low energy density, brown coal is inefficient to transport and is not traded extensively on the world market compared with higher coal grades. It is often burned in power stations constructed very close to any mines, such as in Australia's Latrobe Valley and Luminant's Monticello plant in Texas. Carbon dioxide emissions from brown coal fired plants are generally much higher than for comparable black coal plants. The continued operation of brown coal plants, particularly in combination with strip mining and in the absence of emissions-avoiding technology like carbon sequestration, is politically contentious.[1][2]

Lignite mined in millions of metric tons[citation needed]:

1970 1980 1990 2000 2001
1. Germany 369,300 388,000 356,500 167,700 175,400
2. Russia 127,000 141,000 137,300 86,400 83,200
3. USA 5,400 42,300 82,600 83,500 80,500
4. Australia 24,200 32,900 46,000 65,000 67,800
5. Greece 8,100 23,200 51,700 63,300 67,000
6. Poland 32,800 36,900 67,600 61,300 59,500
7. Turkey 4,400 15,000 43,800 63,000 57,200
8. Czech Republic 67,000 87,000 71,000 50,100 50,700
9. People's Republic of China 13,000 22,000 38,000 40,000 47,000
10. SFR Yugoslavia 26,000 43,000 60,000 - -
10. FR Yugoslavia - - - 35,500 35,500
11. Romania 14,100 27,100 33,500 17,900 29,800
12. North Korea 5,700 10,000 10,000 26,000 26,500
... Total 804,000 1.028,000 1.214,000 877,400 894,800

See also

Energy Portal

References

  1. ^ The Greens Won't Line Up For Dirty Brown Coal In The Valley. Australian Greens Victoria (2006-08-18). Retrieved on 2007-06-28.
  2. ^ Greenpeace Germany Protests Brown Coal Power Stations. Environment News Service (2004-05-28). Retrieved on 2007-06-28.
be-x-old:Буры вугаль
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lignite". A list of authors is available in Wikipedia.
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