Design and development of hydrothermal liquefaction reactor for processing wet lignocellulosic biomass

Wet biomass disposal poses significant environmental challenges, as it is often discarded untreated, contributing to pollution. Hydrothermal liquefaction (HTL) offers a sustainable solution by directly processing wet biomass into energy-rich biocrude, eliminating the need for energy-intensive drying. This study focuses on the design and development of a fiveliter HTL reactor specifically for wet lignocellulosic biomass. The reactor was designed to operate with higher moisture content (60%-80%) at temperatures of 200°C-350°C, and pressures up to 20 MPa. The reactor has a stainless-steel structure with an integrated stirring, heating, and cooling systems. Performance trials with sugarcane bagasse at optimal operating conditions at 275°C, 15 MPa, 40 minutes retention time, and 25% solids loading, demonstrated a maximum biocrude yield of 28%. The process also generated hydrochar (2.3%) and an aqueous phase (54%). The produced biocrude shows potential for direct use as marine fuel or further upgrading for transportation fuels. Hydrochar offers applications in solid fuel, soil amendment, and adsorption, while the aqueous phase presents opportunities for nutrient recovery. This study establishes the feasibility of HTL as an efficient, scalable approach for converting wet biomass into valuable biofuels.