Considering the increase in environmental problems and the possible crisis caused by fossil fuels implies that communities are moving towards the use of renewable energy. Hydrothermal liquefaction (HTL) is a green technology for biocrude production from algae. The overall objective of this research was to examine and produce sustainable fuel from algae. The study plan of this research was divided into two parts. In the first part, exergy, kinetic, and economic analysis of HTL were investigated. Aspen Plus and MATLAB software were used to analyze exergy and economics. A steady-state simulation was performed to calculate the mass and energy flows of HTL process. The pump and heat exchanger were used to pressurize and preheat the feed to the HTL reactor. The preheated feed was converted into HTL products in the reactor. The HTL reactor effluent entered the solids separator, where ash was separated from the reactor products before the effluent flowed into the heat exchanger and cooled. After passing through the depressurizing valve, the products were separated into gas, aqueous, and oil phases in three-phase separator. 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 65856.83 MJ/h 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 for biocrude, as well