EFFECT OF MULTI-AIR STAGED ON NOx EMISSION FROM COAL
COMBUSTION IN CIRCULATING FLUIDIZED BED COMBUSTOR
Chanwit Kamonrat1,*, Prapan Kuchonthara1,2,#
1
Fuels Research Center, Department of Chemical Technology, Faculty of Science,
Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand
2
Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn
University, 254, Phayathai Road, Pathumwan, Bangkok 10330, Thailand
*e-mail: Chanwit.Ka@student.chula.ac.th, #e-mail: prapan.k@chula.ac.th
Abstract
Coal combustion in circulating fluidized bed combustor (CFBC) is an interesting process for
generating power. NOx emission is an important problem from coal combustion that causing
the air pollution. Thus, the reduction of NOx emission should be considered. In this study,
multi-staged air injection in coal combustion was carried out in the CFBC to minimize the
NOx emissions. The effects of primary air and secondary air ratios and the position of
secondary air injection on NOx emissions were investigated. It was found that NOx emission
was reduced when the ratio of primary air and secondary air was decreased. In addition, the
extension of distance between primary and secondary injection points can reduce the NOx
emission. It can be concluded that NOx emission was reduced by operation with the multi-air
staged combustion mode in the CFBC.
Acknowledgements: This research was supported by Fuels Research Center, Department of
Chemical Technology and Center of Excellence on Petrochemical and Materials Technology,
Chulalongkorn University.
Keywords: multi-air staged, coal combustion, NOx emission, CFBC, NOx reduction
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