PM10 formation during the combustion of N2-char and CO2-char of Chinese coals
PM10 formation during the combustion of N2-char and CO2-char of Chinese coals
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DOI：
10.1016/j.proci.2012.07.080
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Chang Wen;Minghou Xu;Dunxi Yu;C. Sheng;Hongwei Wu;Ping’an Zhang;Y. Qiao;H. Yao
中科院分区：
文献类型：
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作者：
Chang Wen;Minghou Xu;Dunxi Yu;C. Sheng;Hongwei Wu;Ping’an Zhang;Y. Qiao;H. Yao
研究了空气燃烧和富氧燃烧条件下煤焦燃烧过程中PM10（空气动力学直径小于或等于10μm的颗粒）的生成规律。三种不同等级的中国煤（即，在1300°C下，在N2和CO2气氛下，在落管式炉（DTF）中分别对DT烟煤、CF褐煤和YQ无烟煤进行脱挥发分。将所得的N2-焦和CO2-焦在空气燃烧（O2/N2=21/79）和氧气燃烧（O2/CO2=21/79）中在1300°C下燃烧。研究了煤焦性质和燃烧条件对煤焦燃烧过程中PM10生成的影响。结果表明，无论是空气燃烧还是富氧燃烧，煤焦燃烧产生的PM10的形成方式和粒径分布与煤粉燃烧的相似。各种煤焦燃烧过程中产生的大量PM0.5（空气动力学直径小于或等于0.5μm的颗粒）表明，煤热解后留在煤焦中的矿物质即使在煤焦燃烧阶段仍对超细颗粒的形成有很大贡献。富氧条件下煤焦燃烧产生的PM10浓度一般小于空气条件下的。CO2-焦的性质不同于N2-焦，这可能是由于煤颗粒在CO2气氛中脱挥发分过程中经历的气化反应。无论燃烧模式，PM10的形成在燃烧的N2-焦和CO2-焦从相同的煤被发现是显着依赖于焦炭性质。N2-半焦和CO2-半焦的PM10生成行为的差异与煤种有关。
The formation of PM10(particles less than or equal to 10μm in aerodynamic diameter) during char combustion in both air-firing and oxy-firing was investigated. Three Chinese coals of different ranks (i.e., DT bituminous coal, CF lignite, and YQ anthracite) were devolatilized at 1300°C in N2and CO2atmosphere, respectively, in a drop tube furnace (DTF). The resulting N2-chars and CO2-chars were burned at 1300°C in both air-firing (O2/N2=21/79) and oxy-firing (O2/CO2=21/79). The effects of char properties and combustion conditions on PM10formation during char combustion were studied. It was found that the formation modes and particle size distribution of PM10from char combustion whether in air-firing or in oxy-firing were similar to those from pulverized coal combustion. The significant amounts of PM0.5(particles less than or equal to 0.5μm in aerodynamic diameter) generated from combustion of various chars suggested that the mineral matter left in the chars after coal devolatilization still had great contributions to the formation of ultrafine particles even during the char combustion stage. The concentration of PM10from char combustion in oxy-firing was generally less than that in air-firing. The properties of the CO2-chars were different from those of the N2-chars, which was likely due to gasification reactions coal particles experienced during devolatilization in CO2atmosphere. Regardless of the combustion modes, PM10formation in combustion of N2-char and CO2-char from the same coal was found to be significantly dependent on char properties. The difference in the PM10formation behavior between the N2-char and CO2-char was coal-type dependent.