生物质再燃NOx脱除特性研究

摘要

Based on biomass directly co-firing,the NOx removal by reburning using sawdust,corn straw and cotton straw was studied in a lab-scale drop tube furnace.Results showed that NOx removal ratio increased with reburning temperature,reburning ratio and decreased excess air ratio in reburning zone.However,due to the formation of thermal-NOx above 1 100 ℃,NOx removal ratio by reburning kept constant or decreased slightly.And NOx removal ratio was also inhibited when the excess air ratio was too low,it is better that the air excess ratio is between 0.6～0.7.In addition,maybe because of higher heating value and lignin content of woody biomass,sawdust possessed higher NOx removal ratio in comparison with agricultural residues like corn straw and cotton straw.%基于生物质直接混燃,在实验室一维沉降炉上研究了锯木屑、玉米秆与棉花秆3种生物质再燃对NO脱除特性的影响.研究结果表明:随再燃区温度升高和再燃比增加,再燃区过量空气系数降低,NOx脱除率升高.当再燃区温度高于l 100℃时,由于热力型NOx的生成,再燃脱氮效果无明显变化,甚至轻微下降;再燃区过量空气系数过度降低,NOx脱除率受到抑制,最佳过量空气系数为0.6～0.7.分析认为,由于木质类生物质较高的热值与木质素含量,锯木屑较农业废弃物玉米秆和棉花秆NOx脱除效率高.