Microalgae has gathered significant interest as a promising feedstock for biocrude production through hydrothermal liquefaction (HTL). However, the challenge of microalgae harvesting presents a significant obstacle to its economic viability and technical feasibility. This study aimed to overcome the complexities of microalgae harvesting processes by exploiting the self-settling characteristic of microalgae Scenedesmus obliquus (S. obliquus). The supernatant was discarded, and the S. obliquus solution was utilized as the processing medium for HTL of various types of biomass. HTL of Chlorella pyrenoidosa (C. pyrenoidosa) in S. obliquus solution at 300 °C resulted in a synergistic increase in biocrude yield (approximately 10 wt%, daf); however, increasing the temperature to 350 °C diminished the observed synergy. HTL of spent coffee grounds in S. obliquus solution generated 39.0 wt% (daf) and 45 wt% (daf) biocrude at 300 °C and 350 °C, respectively, with no synergistic effect observed. Conversely, macroalgae Enteromorpha prolifera (E. prolifera) and sawdust, which had a high carbohydrate content, showed antagonistic effects on biocrude yield when S. obliquus solution was used at high temperatures (350 °C). These observations were further verified by carrying out HTL of carbohydrate model component in S. obliquus solution. Principal component analysis of product yields was performed in this study, and it revealed that HTL of C. pyrenoidosa, protein, and lipid were significantly different from spent coffee grounds, E. prolifera, sawdust, and carbohydrate. Overall, depending on the feedstock used, the self-settling S. obliquus solution could serve as a promising HTL processing medium for biocrude production, eliminating the need for microalgae dewatering processes and the consumption of additional freshwater as an HTL processing medium.

作为通过水热液化 (HTL) 生产生物原油的有前途的原料，微藻引起了人们的极大兴趣。然而，微藻收获的挑战对其经济可行性和技术可行性构成了重大障碍。本研究旨在通过利用微藻斜生栅藻( S. obliquus )的自沉特性来克服微藻收获过程的复杂性。弃去上清液，将斜生链霉菌溶液用作各种生物质的 HTL 处理介质。斜生小球藻( C. pyrenoidosa )的 HTL300 °C 的溶液导致生物原油产量的协同增加（约 10 wt%，daf）；然而，将温度升高到 350 °C 会削弱观察到的协同作用。S. obliquus溶液中用过的咖啡渣的 HTL在 300 °C 和 350 °C 下分别产生 39.0 wt% (daf) 和 45 wt% (daf) 的生物原油，没有观察到协同效应。相反，当在高温（350 °C）下使用S. obliquus溶液时，大型藻类Enteromorpha prolifera（E. prolifera）和锯末具有高碳水化合物含量，对生物原油产量表现出拮抗作用。通过对S. obliquus中的碳水化合物模型成分进行 HTL 进一步验证了这些观察结果解决方案。本研究对产品产量进行了主成分分析，结果表明，蛋白核糖核菌、蛋白质和脂质的 HTL 与用过的咖啡渣、 E. prolifera、锯末和碳水化合物有显着差异。总的来说，根据所使用的原料，自沉斜斜链藻溶液可以作为一种有前途的 HTL 处理介质用于生物原油生产，无需微藻脱水过程，也无需消耗额外的淡水作为 HTL 处理介质。