Amino acids, N-containing compounds, hold a significant importance in various field. Within the biomass energy sector, amino acids constitute a large fraction of the biomass's nitrogen content. As such, it is essential to comprehend their combustion chemistry; most specifically their biomolecular interactions with governing radicals in the pyrolytic and combustion media that prevail during thermal utilization of biomass. Herein, we have employed quantum chemical calculations and reaction rate theory to investigate reactions of a selected set of amino acids with H, CH₃, NH₂, OH, HO₂, and HS radicals. Thermo-kinetic calculations have been performed to determine the rates of hydrogen abstraction by these six radicals across all possible reaction channels for three specific amino acids: alanine, cysteine, and methionine. The investigation of other amino acids like glycine, threonine, and other models have been carried out for α-C positions as the most probable abstractable sites. The study also examines the individual effects of different substituents (COOH, NH₂, HS, and CH₂) and uncovers significant insights. Notably, the presence of the COOH group introduces polar effects that counterintuitively deactivate the thermodynamically favored α-abstraction pathway. Presented thermo-kinetic values are anticipated to complement existing biomass kinetic models and to improve current understanding of chemical events that participate in the complex nitrogen transformation reactions in biomass.

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气相氨基酸与生物质热处理中常见自由基的反应

氨基酸作为含氮化合物，在各个领域都具有重要的重要性。在生物质能源领域，氨基酸占生物质氮含量的很大一部分。因此，了解它们的燃烧化学至关重要；最特别的是它们的生物分子与热解和燃烧介质中的控制自由基的相互作用，这些自由基在生物质的热利用过程中盛行。在此，我们采用量子化学计算和反应速率理论来研究一组选定的氨基酸与H、CH ₃、NH ₂、OH、HO ₂和HS自由基的反应。已经进行了热动力学计算，以确定这六种自由基在三种特定氨基酸（丙氨酸、半胱氨酸和甲硫氨酸）的所有可能反应通道中的夺氢速率。已经对其他氨基酸（如甘氨酸、苏氨酸和其他模型）进行了研究，将α -C 位置作为最可能的可提取位点。该研究还检验了不同取代基（COOH、NH ₂、HS 和 CH ₂）的个体影响并揭示了重要的见解。值得注意的是，COOH 基团的存在引入了极性效应，这违反直觉地使热力学上有利的 α-抽象途径失活。所提出的热动力学值预计将补充现有的生物质动力学模型，并提高目前对参与生物质中复杂氮转化反应的化学事件的理解。