A Techno-Economic Appraisal of Green Diesel Generation through Hydrothermal Liquefaction, Leveraging Residual Resources from Seaweed and Fishing Sectors

This study examines the economic viability of an emerging technology for potential upscaling and commercialization in a specific location: the village of New Stuyahok, Alaska. The proposed technology is hydrothermal liquefaction, which utilizes kelp macroalgae and fishing waste as feedstock. These materials were chosen due to their easy availability in the village and their alignment with the local economy. The economic evaluation is based on the net present value (NPV) and sensitivity models. Different feedstock ratios (on a dry basis), such as 100:0, 50:50, and 30:70 of kelp and fishing waste, respectively, were evaluated to determine the optimal combination. The results indicated that the process is economically viable only when a high proportion of fishing waste is used. This can be ascribed to the constrained output yield of the kelp biomass and the relatively negligible influence exerted by alginate production on the NPV. However, the ratio 50:50 appears to be economically promising if the costs can be reduced by at least 13.5% or the benefits can be increased by 12.1%. Nevertheless, government support could play a crucial role in expediting the implementation of this technology once it becomes market-ready. This means being practical, scalable, and economically viable, enabling reduced investments or increased benefits that signify its readiness. Utilizing such a tool offers valuable insights into the framework of the proposed technology and the use of local natural resources.