再燃煤粉的NO还原特性研究

NO reduction behavior of coal powder used for reburning

实验研究了原煤、煤焦以及煤在不同气氛下受热得到的气体产物对NO的还原特性。结果表明,原煤的NO还原能力不仅与其挥发分含量有关,还与煤中的矿物质有关;制焦气氛中的O2能改变煤焦对NO的还原能力,其改变与煤种有关。高挥发分煤所释放的挥发性产物对NO的还原率也高,但Tongchuan(TC)煤除外。TC煤的挥发分含量不高,但由TC煤得到的挥发物对NO的还原率与高挥发分的Sanxie(SX)和Shenmu(SM)煤释放的挥发物相当。煤在N2环境下所释放的气体产物对NO的还原能力比CO2气氛下释放的气体产物对NO的还原能力强,但TC煤除外。同样,制气气氛中的氧对燃煤挥发物的NO还原能力的影响也很大,这种影响与煤种有关。

The effect of coal,char,and volatiles(obtained from coal under different conditions) on NO reduction behavior has been investigated.The results show that original coal has an ability to reduce NO emission,and its efficiency depends on coal type and minerals within it.Atmosphere and temperature for char-making process influence the behavior of chars in reducing NO emission.Oxygen in char-making atmosphere can change the action of chars depending on coal types.The volatiles released from high-volatile coal have a greater capacity for NO reduction,and the volatiles obtained in N2 have a greater capacity for NO reduction than that obtained in CO2,whereas the minerals in coal can break this trend.O2 in volatile-making atmosphere also affects NO reduction of volatiles depending on coal types.For Tongchuan(TC),it decreases with the increase in amount of O2 added.For Sanxie(SX),Shenmu(SM),and Jiaozuo(JZ),the best NO reduction efficiency appears when the amount of O2 added is 3%.