Occurrence of inorganic elements in condensed volatile matter emitted from coal pyrolysis and their contributions to the formation of ultrafine particulates during coal combustion
Occurrence of inorganic elements in condensed volatile matter emitted from coal pyrolysis and their contributions to the formation of ultrafine particulates during coal combustion
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DOI：
10.1021/ef050429h
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发表时间：
2006-05
期刊：
影响因子：
5.3
通讯作者：
Lian Zhang;Y. Ninomiya;T. Yamashita
中科院分区：
文献类型：
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作者：
Lian Zhang;Y. Ninomiya;T. Yamashita
煤热解是煤燃烧过程中的第一步，当注入的煤颗粒膨胀时，在很短的停留时间内释放挥发分（VM）。同时，固有金属的有机结合部分也可能被排放出来。为了证实煤中有机结合金属的存在，在实验室规模的落管式炉中，在N2气氛下对五种烟煤和一种无烟煤进行了热解。炉内的气体温度约为900 - 1400 K，因此除了含有Na的元素之外，几乎所有的无机元素都难以蒸发。排放的VM由低压冲击器收集。结果表明，小于1.0 μm的凝聚态VM（CVM）为无定形碳结构，其中也含有无机元素。硫是最普遍的，其次是钠，硅，氯，钙，和其他按降序排列。TEM-ED和SEM-SEM都表明，除一部分钠以NaCl形式存在外，所有无机元素都与CVM有机结合。
Coal pyrolysis is the first step during coal combustion, when the injected coal particles swell to release the volatile matter (VM) at a very short residence time. Simultaneously, the organically bound fraction of inherent metals is likely emitted out too. To prove the presence of organically bound metals in coals, five bituminous coals and one anthracite coal from China were pyrolyzed in N2 in a lab-scale drop tube furnace. The gas temperature in furnace was about 900−1400 K so that almost all the inorganic elements except those containing Na hardly vaporized. The emitted VM was collected by a low-pressure impactor. The results indicate that the condensed VM (CVM) smaller than 1.0 μm has an amorphous carbon structure, which contains the inorganic elements too. Sulfur is the most prevalent, followed by sodium, silicon, chlorine, calcium, and others in the decreasing order. Apart from a portion of sodium in form of NaCl, all the inorganic elements are organically bound with CVM as determined by both TEM-ED...