본 연구에서는 2 MWe 규모 순환유동층 발전소에서 중국산 유연탄과 북한산 무연탄의 혼합연소특성을 실험적으로 고찰하였다. 중국유연탄과 호주유연탄을 과잉공기량과 층온도 등을 변수로 실험한 결과, 연소효율은 석탄입자의 입도와 석탄중의 휘발분의 영향을 받으며, 이 때 미연탄소분은 Fly ash 5~7%, 바닥회 0.3% 수준으로 중국 유연탄의 연소효율은 99.5% 이상을 보였다. 북한산 무연탄과 유연탄의 혼소시 혼합비 20%에서 무연탄의 평균입도가 작아 연소실에서 비산되는 입자로 인해 연소효율은 5% 이상 저하되었다, 그러나 SO2와 NOx의 배출농도는 크게 변화하지 않았다. 배출되는 대기오염물질의 농도는 NOx 200~250 ppm(O2 6%), SO2 100~320 ppm(O2 6%)이었다. SCR 공정에서 2~13 l/min 범위의 NH3 공급으로 30~65%의 NOx가 저감되었다. Limestone을 이용한 노내탈황에서 약 Ca/S 몰비 6.5를 공급했을 때 SO2가 75% 제거되었고, Mg(OH)2를 흡수제로 하는 FGD를 운전했을 때 pH 5.0 이상에서 100% 탈황효과를 보였다.

In this study, co-combustion characteristics of Chinese bituminous coal and North Korean anthracite were investigated using a 2 MWe scale circulating fluidized bed power plant. At first, the combustion efficiency of bituminous coal of China and Australia as a function of excess air ratio and temperature were observed. The results showed that the combustion efficiency was influenced by particle size and volatile content of coal, the combustion efficiency of Chinese_x000D_ bituminous coal was over 99.5%. The unburned carbon particles from fly ash and bottom ash were a content 5~7% and 0.3%, respectively. The combustion efficiency with the mixture ratio 20% of bituminous coal and anthracite decreased over 5% because of the increase of entrained particles by a small average particle size of anthracite in the combustor. However, the outlet concentration of SO2 and NOx was not changed remarkably. The concentrations of the typical air pollutants such as NOx and SO2 were 200~250 ppm(O2 6%), 100~320 ppm(O2 6%) respectively. The outlet concentration of NOx was decreased to 30~65% with NH3 supplying rate of 2~13 l/min in SCR process. The SOx removal efficiency was up to 70% by in-furnace desulfurization using limestone with Ca/S molar of approximately 6.5. With wet scrubbing using Mg(OH)2 as absorbent, the SOx removal efficiency reached 100% under near pH 5.0 of scrubbing liquid.

Circulating Fluidized Bed Coal Combustion Flue Gas Emission Co-Combustion

James K, Massachusetts Institute of Technology, 5 (2007)
Shun D, Jin KT, Yi CK, Han KH, Research Report, KIER-A03707, KIER, 7-12 (2000)
Jin KT, Han KH, Shun D, Park JH, Research Report, KIER-973402, KIER, 31-34 (2000)
Koskinen, Proceeding of the 13th International Conference on FBC (1995)
Han KH, Ryu JI, Jin KT, Trans. of the KSME(B), 25, 1373 (2001)
Sarofim AF, Goel SK, Morihara A, International Clean Coal Technology Symposium on PFBC, 12-27 (1994)
Han KH, Kang SH, Ryu JI, Jin GT, HWAHAK KONGHAK, 39(5), 557 (2001)
Han KH, Song YS, Ryu JI, Son JE, Jin GT, HWAHAK KONGHAK, 41(1), 86 (2003)
Kang SH, Han KH, Jin GT, Kang Y, J. Korean Ind. Eng. Chem., 13(1), 37 (2002)
Shimizu T, Fujita D, Ishizu K, Kobayashi S, Inagaki M, Proc. of 12th International Conference on Fluidized Bed Combustion, 611 (1993)
Shun D, Bae DH, Han KH, Son JE, Kang Y, Wee YH, Lee JS, Ji PS, HWAHAK KONGHAK, 34(3), 321 (1996)
Leckner B, Prog. Energy Combust. Sci., 24(1), 31 (1998)
Ake TR, Dixit VB, Mongeon RK, Proc. of 12th International Conference on Fluidized Bed Combustion, 81 (1993)
Han KH, Park J, Ryu JI, Jin GT, Korean J. Chem. Eng., 16(6), 804 (1999)