Influence of steam on NO formation during oxy-coal combustion

doi:10.3969/j.issn.0438-1157.2014.11.050

Abstract

Abstract: The influence of H₂O on NO formation during oxy-coal combustion was investigated in a drop-tube furnace. A bituminous coal was selected and burnt at temperature of 1273 K under O₂/N₂, O₂/CO₂ and O₂/CO₂/H₂O atmospheres, respectively. At different O₂ contents 5%, 21%, and 30%, the samples were analyzed for increasing residence time from 0.2 s to 1.1 s. The results show that NO formation is suppressed by addition of H₂O. The mechanism of NO reduction is due to the change of volatile-N chemistry with H₂O addition. The H₂O influence on homogeneous NO formation goes up with the increase of O₂ concentration.

Key words: coal, oxy-coal combustion, NO

摘要： 为了研究H₂O对燃料N向NO转化各个阶段的影响,采用可沿程取样的沉降炉反应器,研究了一种烟煤在1273 K温度下,O₂/N₂、O₂/CO₂以及O₂/CO₂/H₂O气氛下燃烧的燃尽与NO生成的情况.并通过在停留时间为0.2、0.3、0.5、1.1 s与O₂浓度为5%、21%及30%情况下的实验来研究H₂O对NO生成的影响.实验结果表明,相对于O₂/CO₂气氛,H₂O的添加抑制了NO的生成,且该影响主要集中在燃烧初期挥发分N的氧化过程.随着O₂浓度的增加,H₂O添加对oxy-coal燃烧方式下NO生成影响加大.

关键词: 煤, 氧燃料燃烧方式, NO

CLC Number:

X705

HU Xiaowei, WU Wangchen, YAO Hong. Influence of steam on NO formation during oxy-coal combustion[J]. CIESC Journal, 2014, 65(11): 4564-4570.

胡晓炜, 吴望晨, 姚洪. 水蒸气对oxy-coal燃烧中NO生成的影响[J]. 化工学报, 2014, 65(11): 4564-4570.

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