Bio-oil, obtained from the pyrolysis of biomass, is identified as a potential material for producing transportation fuels and value-added chemicals. However, the physical and chemical properties of bio-oil change with time, known as “aging,” and the instability of bio-oil brings a critical hurdle to the commercial application of bio-oil. Therefore, expanding and deepening the understanding of the aging mechanism of bio-oil is the key to later efficient application of bio-oil. In addition, the extreme complexity of pyrolysis bio-oil composition brings great difficulties in studying the aging mechanism. Thus, this study tries to better understand the aging mechanism by evaluating the aging performance for 39 model compound aging tests performed at 80°C for 72 h. Four kinds of reactions (self-condensation, esterification, aldol condensation, and phenol, and aldehyde reaction) were investigated to understand the contribution of various compounds and reactions during the aging process. It has been found that acids played an important role in the aging process, as these acted as the reactant in the esterification reaction and acted as the catalyst for aldol condensation and phenol and aldehyde reaction. Acids and alcohols reacted via the esterification reaction, resulting in the decline of aliphatic C-O bonds. Due to the absence of acids, aromatic compounds were relatively stable in these tests. In comparison, aldehydes and HMF were active since self-condensation reactions for these chemicals were observed in the absence of acids. Moreover, with the aid of acids, HMF showed high tendency toward polymerization during the accelerated aging process.

从生物质热解获得的生物油被确定为生产运输燃料和增值化学品的潜在材料。但是，生物油的物理和化学特性会随着时间而变化，这被称为“老化”，而生物油的不稳定性给生物油的商业应用带来了关键的障碍。因此，扩大和加深对生物油老化机理的理解是以后生物油高效利用的关键。另外，热解生物油组合物的极端复杂性给研究老化机理带来很大困难。因此，本研究试图通过评估在80°C下进行72小时的39种模型化合物的老化测试的老化性能来更好地理解老化机理。四种反应（自缩合，酯化，羟醛缩合，（苯酚和醛反应）进行了研究，以了解老化过程中各种化合物和反应的贡献。已经发现，酸在老化过程中起重要作用，因为它们在酯化反应中起反应物的作用，并在醇醛缩合和酚醛反应中起催化剂的作用。酸和醇反应通过酯化反应，导致脂肪族CO键下降。由于不存在酸，因此芳香族化合物在这些测试中相对稳定。相比之下，醛和HMF具有活性，因为在没有酸的情况下观察到这些化学物质的自缩合反应。此外，在酸的帮助下，HMF在加速老化过程中表现出很高的聚合趋势。