Biomass (especially algae) is a renewable energy source that can be a great alternative to fossil fuels. Wet algal biomass converts into products such as solid, aqueous, and gaseous phases as well as biocrude in hydrothermal liquefaction (HTL). The aim of this work was to provide detailed exergy analyses of the production of biocrude from Nannochloropsis sp. by HTL. Physical and chemical exergy of the HTL products, exergy losses, exergy efficiency, and exergy distribution of the HTL process were determined in this research. The highest exergy loss and the lowest efficiency values obtained for the heat exchanger were 65,856.83 MJ/hr and 66.64%, respectively, which was mainly caused by the irreversibility of the heat transfer process. Moreover, the HTL reactor had high efficiency (99.9%) due to the complex reactions that occurred at high temperature and pressure. Also, the optimum operating conditions of the reactor were obtained at 350 °C and 20 MPa by using sensitivity analysis. The high overall exergy efficiency of the process (94.93%) indicated that HTL was the most effective process for the conversion of algae. In addition, the exergy recovery values of the overall exergy input values in the HTL process for biocrude, as well as the aqueous, solid, and gas phases, were nearly 74.88%, 18.42%, 0.86%, and 0.76%, respectively. Exergy assessment provides beneficial information for improving the thermodynamic performance of the HTL system.

生物质（尤其是藻类）是一种可再生能源，可以很好地替代化石燃料。湿藻类生物质在水热液化 (HTL) 中转化为固体、水相和气相以及生物原油等产品。这项工作的目的是提供从微绿球藻生产生物原油的详细火用分析sp. 通过 HTL。本研究确定了 HTL 产品的物理和化学火用、火用损失、火用效率和 HTL 过程的火用分布。换热器获得的最高火用损失和最低效率值分别为 65,856.83 MJ/hr 和 66.64%，这主要是由于传热过程的不可逆性造成的。此外，由于在高温和高压下发生复杂的反应，HTL 反应器具有高效率（99.9%）。此外，反应器的最佳运行条件是在 350 °C 和 20 MPa 下通过​​使用灵敏度分析获得的。该过程的高整体火用效率 (94.93%) 表明 HTL 是最有效的藻类转化过程。此外，生物原油 HTL 工艺以及水相、固相和气相的总火用输入值的火用回收率分别接近 74.88%、18.42%、0.86% 和 0.76%。火用评估为改进 HTL 系统的热力学性能提供了有益的信息。