Effects of molecular O-2 and NO2 on particle size distribution, morphology and nanostructure of diffusion flame soot oxidized in a flow reactor
Effects of molecular O-2 and NO2 on particle size distribution, morphology and nanostructure of diffusion flame soot oxidized in a flow reactor
复制标题
分子O-2和NO2对流动反应器中扩散火焰氧化烟灰粒径分布、形貌和纳米结构的影响
DOI：
10.1016/j.fuel.2018.07.039
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发表时间：
2018
期刊：
影响因子：
7.4
通讯作者：
Huang Zhen
中科院分区：
文献类型：
--
作者：
Liu Chunpeng;Zhu Lei;Gao Zhan;Li Haozhen;Huang Zhen
在流动反应器中研究了不同温度下烟尘颗粒在o2和no2气氛中的氧化过程。使用乙烯扩散火焰产生颗粒，并使用喷射器稀释器取样系统在火焰尖端取样。烟尘在流动反应器中被三种稀释气体（纯N2、10000 ppm O2with N2和10000 ppm NO2with N2）氧化，用DMS500、透射电子显微镜（TEM）、高分辨率透射电子显微镜（TEM）、拉曼显微镜（Raman microscopy）和热重分析（TGA）进行测量。结果表明：随着氧化温度的升高，烟尘颗粒的粒径、初粒径、团聚度和浓度均减小；在低温（200和400 °C）下no2的整体氧化能力强于o2，而在高温（600和800 °C）下o2的整体氧化能力强于o2。烟灰在o2和NO2氧化过程中存在内外氧化。随着温度的升高，晶格的平均条纹长度增加，晶格的扭曲度和烟灰颗粒的Id/ ig比减小，表明烟灰颗粒的纳米结构变得更加有序。上述多重诊断结果表明，在整个氧化过程中，氧化主要有三种形式：内部氧化、外部氧化和内部塌陷。在高温（600和800 °C）下，o2的氧化以内部氧化和内部坍塌为主，而no2的氧化在整个氧化温度范围内以外部氧化为主。
The oxidation process of soot particles in O2and NO2atmospheres is investigated in a flow reactor at various temperatures. The particles are generated using an ethylene diffusion flame and sampled at the tip of the flame using an ejector diluter sampling system. Soot is oxidized by three kinds of diluted gas (pure N2, 10000 ppm O2with N2and 10000 ppm NO2with N2) in the flow reactor and measured with DMS500, transmission electron microscopy (TEM), high-resolution TEM, Raman microscopy and thermogravimetric analysis (TGA). The results show that the particle size, primary particle diameter, agglomeration degree and concentration of soot particles decrease as the oxidation temperature increases. The overall oxidation capacity of NO2is stronger than that of O2at low temperatures (200 and 400 °C), whereas at high temperatures (600 and 800 °C) O2is stronger. Both internal oxidation and external oxidation exist during the oxidation process of soot with O2and NO2. The average fringe length of the lattice increases and the tortuosity of the lattice and the Id/Igratios of the soot particles decrease as temperature increases, meaning that the nanostructure of the soot particles becomes more ordered. The results of the multi-diagnostics above indicate three main forms of oxidation during the overall oxidation process: internal oxidation, external oxidation and internal collapse. The oxidation of O2is dominated by internal oxidation and internal collapse at high temperatures (600 and 800 °C), whereas the oxidation of NO2is dominated by external oxidation throughout the oxidation temperature range.