In this work, four types of torrefaction atmosphere (N₂, 14% O₂, CO₂, and NH₃) were employed during torrefaction pretreatment to regular the element distribution of biomass, then the effect of torrefaction pretreatment on subsequent pyrolysis behaviors was investigated. After torrefaction pretreatment, the content of carbon increased, while the content of oxygen sharply decreased. CO₂ atmosphere resulted in highest content of carbon, and NH₃ atmosphere resulted in lowest content of oxygen and highest content of nitrogen. The residual mass in TG curve increased after torrefaction pretreatment, resulting in lower mass loss rate at the DTG peaks. Meanwhile, the release amounts of H₂O, CH₄, CO₂, and CO were highly related to the element distribution in torrefied biomass. As the increase of torrefaction temperature, the contents of ketones and acids decreased, while the content of phenols increased. Compared to other three types of torrefaction atmospheres (N₂, CO₂, and 14%O₂), NH₃ atmosphere resulted in lowest content of acids because of the Maillard reactions where majority of carbonyl group in the biomass was replaced by the NH₂*/NH* radicals. Thus, some nitrogen-containing components was detected after the NH₃ torrefaction pretreatment because of the incorporation of nitrogen element in torrefied biomass.

在这项工作中，在烘焙预处理过程中采用了四种烘焙气氛（N ₂、14% O ₂、CO ₂和 NH ₃）来调节生物质的元素分布，然后研究了烘焙预处理对后续热解行为的影响. 烘焙预处理后，碳含量增加，而氧含量急剧下降。CO ₂气氛导致碳含量最高，NH ₃气氛导致氧含量最低，氮含量最高。烘焙预处理后TG曲线中的残留质量增加，导致DTG峰处的质量损失率降低。同时，H 的释放量₂ O、CH ₄、CO ₂和CO 与烘焙生物质中的元素分布高度相关。随着烘焙温度的升高，酮和酸的含量降低，而酚类的含量增加。与其他三种类型的烘焙气氛（N ₂、CO ₂和 14%O ₂）相比，NH ₃气氛导致酸含量最低，这是因为生物质中的大部分羰基被 NH ₂取代的美拉德反应*/NH* 自由基。因此，在 NH ₃ 由于在烘焙生物质中掺入了氮元素，因此进行了烘焙预处理。