(328a) Techno-Economic Assessment of Biofuel Production from the Hydrothermal Liquefaction of Macroalgae

The hydrothermal liquefaction (HTL) of macroalgae has garnered considerable attention as a promising environmentally sustainable method for producing renewable fuels and other high-value chemicals. In this comprehensive study, we conducted an extensive techno-economic analysis (TEA) and life cycle assessment to evaluate the feasibility, economic viability, and environmental impact of developing a commercial-scale HTL process for converting macroalgae into valuable products. We leveraged experimental data to develop a TEA model for the HTL of 25 metric tons per hour (MT/hr) of macroalgae to produce 5.26MT/hr of biofuel within the gasoline and diesel range fuel. Two cases were evaluated: a conventional case with HTL experimental testing results underlining the major design basis, and an intensified case considering future improvements for a commercial plant with advanced technologies. Process simulation and cost estimates were conducted to evaluate the total project investment and operating cost to 221M$ and 155M$/year, respectively. The annual production rate for the final biocrude was estimated to be 22.5 and 39.9 million gallons of gasoline equivalent (GGE) for the conventional and the intensified cases, respectively. The minimum fuel selling price (MFSP) based on the assumption of a 10% internal rate of return and 30 years of plant life was estimated to be $11/GGE for the conventional case and $8/GGE for the intensified case. We performed a sensitivity analysis to highlight the key variables influencing the target scenario, underscoring the cost uncertainties associated with the assumed variations in selected parameters. Our results showed that product separation strongly influences the MFSP, reducing production costs when moving from the conventional to the intensified case.