Quantitative Analysis of NOx Reduction in Oxy-Coal Combustion

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• 作者：Yongchun Zhang ; Jun Zhang ; Changdong Sheng ; Yangxian Liu ; Liang Zhao ; Qizhong Ding
• 刊名：Energy & Fuels
• 出版年：2011
• 出版时间：March 17, 2011
• 年：2011
• 卷：25
• 期：3
• 页码：1146-1152
• 全文大小：971K
• 年卷期：v.25,no.3(March 17, 2011)
• ISSN：1520-5029

文摘

The conversion ratios of fuel-N to NO were investigated during combustion of two Chinese bituminous coals in four different atmospheres (O₂/N₂, O₂/Ar, O₂/CO₂, and O₂/RFG) in an electrically heated drop-tube furnace at elevated temperatures (1273鈭?673 K). The oxygen concentration in the inlet gas was changed from 8% to 40%. The recycling ratio of flue gas ranged from 0.4 to 0.8. Through comparing the conversion ratios of fuel-N to NO among the four different atmospheres, the contributions of elimination of atmospheric nitrogen, high CO₂ concentration in the furnace, and reduction of recycled-NO_x to the reduction of total NO_x in oxy-coal combustion were investigated. Results show that the contribution of recycled-NO reduction was dominant. It contributed 45鈭?0% of the total reduction of NO_x. It decreased with oxygen concentration in the inlet gas and increased with flue gas recycling ratio. The contribution of elimination of atmospheric nitrogen accounted for 12鈭?5% and had a trend opposite that observed for the recycled-NO reduction. The contribution of the high CO₂ concentration in the furnace accounted for 18鈭?3%. It initially increased with oxygen concentration, and then decreased as the oxygen concentration reached and exceeded 21%. The influence of temperature on the contributions of elimination of atmospheric nitrogen, high CO₂ concentration in the furnace, and reduction of recycled-NO_x to the reduction of total NO_x was complex. It depended on combustion conditions and the type of employed coals.