Effect of circulating ash from CFB boilers on NO and N2O emission
Received date: 01 Jul 2008
Accepted date: 16 Aug 2008
Published date: 05 Jun 2009
Copyright
NO and N2O emissions from circulating fluidized bed (CFB) boilers are determined by their formation and destruction rates in the furnace. The effect of circulating ash from a CFB boiler on NO and N2O emissions were investigated in a laboratory-scale fluidized bed reactor. The results show that the residue char in circulating ash and the CO generated from the char play an important role in NO reduction and N2O formation; however, active components of circulating ash such as CaO, Fe2O3 accelerate the decomposition of N2O. Experiment was also conducted on a 75 t/h CFB boiler fueled with the mixture of anthracite and biomass. The lower residue carbon content of circulating ash in this experiment is lower; therefore, the reacting rate of NO deoxidize is limited. This result verified the conclusion of laboratory research.
Key words: CFB boiler; circulating ash; NO reduction; N2O thermal decomposition; biomass
Xiangsong HOU , Shi YANG , Junfu LU , Hai ZHANG , Guangxi YUE . Effect of circulating ash from CFB boilers on NO and N2O emission[J]. Frontiers in Energy, 2009 , 3(2) : 241 -246 . DOI: 10.1007/s11708-009-0006-0
1 |
Feng Junkai, Yue Guangxi, Lv Junfu. Circulating Fluidized Bed Combustion Boiler. Beijing: China Electric Power Press, 2003 (in Chinese)
|
2 |
Gani A, Naruse I. NO and N2O formation/decomposition characteristics during co-combustion of coal with biomass. In: Lia L, ed. Proceedings of the 18th International Conference on Fluidized Bed Combustion. Toronto: ASME, 2005, FBC2005-78024
|
3 |
Zhang H, Lu J F, Chen K Y,
|
4 |
x000c5;mend L, Leckner B. Reduction of N2O in a circulating fluidized-bed combustor. Fuel, 1994, 73(9): 1389-1397
|
5 |
Armesto L, Boerrigter H, Bahillo H,
|
6 |
Zhang Yi, Chen Biao, Ding Yanjun,
|
7 |
Zhao Zongbing, Li Wen, Li Baoqing. Catalytic reduction of NO by chars loaded with Ca and Fe. Environmental Science, 2001, 22(5): 17-20(in Chinese)
|
8 |
Molina A, Eddings E G, Pershing D W,
|
9 |
Ren Wei, Xiao Xianbing, Lv Junfu. Research on conversion of nitrogen in char during combustion under fluidized bed conditions. Journal of China University of Mining & Technology, 2003, 32(3): 259-262 (in Chinese)
|
10 |
Hayhurst A N, Lawrence A D. The reduction of the nitrogen oxides NO and N2O to molecular nitrogen in the presence of iron, its oxides, and carbon monoxide in a hot fluidized bed. Combustion and Flame, 1997, 110(3): 351-365
|
11 |
Löffler G, Wargadalam V J, Winter F,
|
12 |
Barišic V, Neyestanaki A K, Klingstedt F,
|
13 |
Hou Xiangsong, Li Jinping, Zhang Hai,
|
14 |
Winter F, Wartha C, Hofbauer H. NO and N2O formation during the combustion of wood, straw, malt waste and peat. Bioresource Technology, 1999, 70(1): 39-49
|
15 |
Kilpinen P, Kallio S, Konttinen J,
|
16 |
Yang Shi, Hou Xiangsong, Yang Hairui,
|
17 |
Liu Hao, Gibbs B M. Modeling of NO and N2O emissions from biomass-fired circulating fluidized bed combustors. Fuel, 2002, 81(3): 271-280
|
/
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