For second-generation (2 G) cellulosic ethanol production to be sustainable and viable, there is the need to value-add to the stillage. Here, pilot plant-derived 2G ethanol sugarcane bagasse stillage (BS) and eucalyptus stillage (ES) was transformed into valuable products using hydrothermal liquefaction (HTL) at 300 °C and 20 bar with Pd/C and K₂CO₃. BS produced oil, phenolic monomers, and organic acid yields of 32 %, 49 % and 25 % respectively, while yields for ES were lower. Catechol constituted 43 % of the total phenolic content for BS. Recycling the aqueous phase (containing acetic, formic, lactic, and propionic acids) improved phenol, guaiacol and catechol yields. Oil stability tests indicated a significant drop in oil yield with aging, but there was no significant change in higher heating value. A preliminary techno-economic analysis suggests that the potential value of producing 2G ethanol and products (including fertilizer) from BS is three times that of depithed sugarcane bagasse. This study demonstrated a potential technology to convert 2 G cellulosic ethanol stillage to value-added chemicals, which not only improved the efficiency and profitability of 2G ethanol production but reduced organic contaminants synthesis.

为了使第二代 (2G) 纤维素乙醇生产可持续和可行，需要对酒糟进行增值。在这里，中试植物来源的 2G 乙醇甘蔗渣酒糟 (BS) 和桉树酒糟 (ES) 在 300 °C 和 20 bar 条件下使用 Pd/C 和 K ₂ CO _{3 的}水热液化 (HTL) 转化为有价值的产品. BS 产生的油、酚类单体和有机酸的产率分别为 32%、49% 和 25%，而 ES 的产率较低。儿茶酚占 BS 总酚含量的 43%。回收水相（含有乙酸、甲酸、乳酸和丙酸）提高了苯酚、愈创木酚和儿茶酚的产量。油稳定性测试表明，随着老化，油产率显着下降，但较高的热值没有显着变化。初步的技术经济分析表明，从 BS 生产 2G 乙醇和产品（包括肥料）的潜在价值是脱髓甘蔗渣的三倍。这项研究展示了一种将 2 G 纤维素乙醇酒糟转化为增值化学品的潜在技术，