Abstract Heat pretreatment is a promising method for biomass upgrading. However, PM formation from the combustion of such pretreated biomass has not been fully evaluated. In this work, the effect of pretreatment temperature on PM emission of the upgraded biomass and biochar combustion was studied in an entrained flow reactor. The physical and chemical properties of upgraded biomass, biochar and PMs at varied pretreatment temperatures were obtained to illustrate the PM formation mechanism. Results show that pretreatment temperature significantly affects the concentration and particle size distribution of PM emissions, through changing the char yield and K/Cl contents in char. With increase in pretreatment temperature, the PM1.0 emission of upgraded biomass and biochar combustion first increases, reaches maximum at 500 °C, and then decreases. A linear relationship between the PM1.0 emission and Cl content in upgraded biomass and biochar was found. This result indicates that the combustion of upgraded biomass and biochar produced at moderate temperatures of 250–500 °C result in aggravated fouling and PM emissions.

中文翻译：

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加热升级的生物质和生物炭燃烧导致细颗粒物排放加剧：预处理温度的影响

摘要 热处理是一种很有前景的生物质升级方法。然而，这种预处理生物质燃烧产生的 PM 尚未得到充分评估。在这项工作中，在夹带流反应器中研究了预处理温度对升级后的生物质和生物炭燃烧的 PM 排放的影响。获得了在不同预处理温度下升级的生物质、生物炭和 PM 的物理和化学性质，以说明 PM 的形成机制。结果表明，预处理温度通过改变焦炭产率和焦炭中 K/Cl 含量显着影响 PM 排放物的浓度和粒径分布。随着预处理温度的升高，提质生物质和生物炭燃烧的PM1.0排放先增加，在500℃达到最大值，然后降低。发现升级后的生物质和生物炭中 PM1.0 排放量与 Cl 含量之间存在线性关系。该结果表明，在 250-500 °C 的中等温度下生产的升级生物质和生物炭的燃烧会导致结垢和 PM 排放加剧。