Effects of Reaction Condition on the Emission Characteristics of Fuel-N during the O-2/H2O Combustion Process of Demineralized Coal
Effects of Reaction Condition on the Emission Characteristics of Fuel-N during the O-2/H2O Combustion Process of Demineralized Coal
复制标题
反应条件对脱盐煤O-2/H2O燃烧过程中燃料-N排放特性的影响
DOI：
10.1021/acs.energyfuels.9b01031
复制
发表时间：
2019
期刊：
影响因子：
5.3
通讯作者：
Ren Xiaohan
中科院分区：
文献类型：
--
作者：
Wang Zhuozhi;Li Yupeng;Zhu Wenkun;Sun Rui;Zhao Yaying;Ren Xiaohan
研究了神华烟煤在O2/H2O燃烧过程中燃料氮的排放和演化特性。为了避免碱金属盐的催化干扰，本研究采用从原煤样品中获得的脱矿煤进行研究。研究了影响煤燃烧特性的两个重要因素--反应温度（Tr）和H2O浓度对燃料氮排放特性的影响。在不同的O2/H2O条件（Tr：1073和1473 K; O2：30%; H2O：0，3.5，8.5，15，20，和30体积%）下进行的等温燃烧试验表明，相对高浓度的N2 O，HCN，和NH3的测量在O2/H2O燃烧的煤样。随着Trand H_2O浓度的增加，反应的挥发分/挥发份氧化阶段燃料氮的释放量增加。脱挥发分后半焦的X射线光电子能谱（XPS）结果表明，在高温反应初期，大部分N-5分解为HCN或转化为N-6或N-Q，N-Q是半焦表面含氮官能团（C（N））的主要形式。在整个O2/H2O燃烧过程中，O2/H2O挥发分脱除后半焦的还原性对降低NO的排放起着至关重要的作用。
This research investigated the emission and evolution characteristics of fuel-N during the O2/H2O combustion process of a typical bituminous coal (Shenhua). To avoid the catalytic interference of alkali metal salts, the demineralized coal obtained from the raw coal sample was employed for the investigation in this research. The effects of reaction temperature (Tr) and H2O concentration, which were two vital factors affecting coal combustion characteristics, on the emission characteristics of fuel-N during the combustion process were also taken into consideration. Isothermal combustion tests performed under different O2/H2O conditions (Tr: 1073 and 1473 K; O2: 30%; H2O: 0, 3.5, 8.5, 15, 20, and 30 vol %) indicated that relatively high concentrations of N2O, HCN, and NH3were measured in the O2/H2O combustion of the coal sample. With the increase ofTrand H2O concentration, more fuel-N would be released in the devolatilization/volatile oxidation stage of the reaction. The X-ray photoelectron spectroscopy results of chars after devolatilization indicated that most of the N-5 decomposed into HCN or converted to N-6 or N-Q in the early reaction stage at high temperatures and that N-Q was the dominated form of a nitrogen-containing functional group (C(N)) existing on the char particle surface. The reducibility of the chars after O2/H2O devolatilization played vital roles in reducing the emission of NO during the whole O2/H2O combustion process.