Abstract Specific surface areas of particles produced at small-scale diffusion flame burners and also in pilot and large-scale fires involving complex fuels are reported and compared. Specific surface area SBET is determined by BET (Brunauer-Emmett-Teller) analysis and also according to previously developed approach STEM relying on the primary sphere based on TEM (Tansmission Electron Microscopy) images analysis. True density is also determined and the respective influences of primary particle diameter (Dpp) and organic carbon to total carbon ratio (OC/TC) are discussed. The present study is the first to propose a careful comparison between TEM and BET specific surface areas of 20 different samples of carbonaceous particles emitted under realistic fire conditions and to bring validity range for such TEM based approach. For samples containing low and moderate OC content (less than 20%), a good agreement between STEM and SBET is reported (within ± 20% for a confidence interval of 95%), confirming the significant influence of primary particle diameter and the relevance of a purely geometrical description of the surface specific area of soot particles. For larger OC/TC, such approach fails to predict the particles specific surface area within a reasonable confidence interval.

中文翻译：

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燃烧排放颗粒的比表面积：初级颗粒直径和有机物含量的影响

摘要 报告并比较了小规模扩散火焰燃烧器以及涉及复杂燃料的中试和大规模火灾中产生的颗粒的比表面积。比表面积 SBET 通过 BET (Brunauer-Emmett-Teller) 分析以及根据先前开发的 STEM 方法确定，该方法依赖于基于 TEM（透射电子显微镜）图像分析的初级球体。还确定了真密度，并讨论了初级粒径 (Dpp) 和有机碳与总碳比 (OC/TC) 的各自影响。本研究首次提出了在真实火灾条件下排放的 20 种不同碳质颗粒样品的 TEM 和 BET 比表面积之间的仔细比较，并为这种基于 TEM 的方法带来了有效范围。对于含有低和中等 OC 含量（小于 20%）的样品，据报道 STEM 和 SBET 之间具有良好的一致性（对于 95% 的置信区间在 ± 20% 内），证实了初级粒径的显着影响和烟灰颗粒表面积的纯几何描述。对于较大的 OC/TC，这种方法无法在合理的置信区间内预测颗粒比表面积。