The impact of reaction temperatures on the liquefaction behavior of lignin in the two-step liquefaction process with different residence times were studied. Results showed that the bio-oil yield of lignin pretreated with supercritical CO2-subcritical ethanol was increased 21.4 wt% compared with that of direct liquefaction at 320 °C and 30 min. In the depolymerization stage, the low temperature was helpful to the depolymerization reaction, resulting in the highest oil yield of 63.4 wt% at 245 °C and 15 min. Meanwhile, the increasing reaction temperature promoted alkylation and hydrodeoxygenation, and the highest phenolic content was 56.8% at 320 °C and 30 min. Additionally, the H/C and O/C of the bio-oil were 1.3 and 0.2, respectively, corresponding to the HHV of bio-oil of 32.8 MJ/kg.

研究了不同停留时间的两步液化过程中反应温度对木质素液化行为的影响。结果表明，与在320°C和30分钟直接液化相比，用超临界CO2-亚临界乙醇预处理的木质素的生物油产率提高了21.4 wt％。在解聚阶段，低温有助于解聚反应，在245°C和15分钟时，最高油产率为63.4 wt％。同时，升高的反应温度促进了烷基化和加氢脱氧，在320℃和30min时最高酚含量为56.8％。此外，生物油的H / C和O / C分别为1.3和0.2，对应于生物油的HHV为32.8 MJ / kg。