(180aj) Hydro-Oil Production Characteristics from Co-Hydrothermal Liquefaction of Ecklonia Cava and Waste Plastic

Hydrothermal liquefaction (HTL) is an emerging thermochemical process for converting wet biomass and organic waste into energy-dense bio-crude oils (hydro-oils). In this study, co-liquefaction of Ecklonia cava, a brown macroalgae rich in carbohydrates and proteins, with waste plastic was conducted to explore synergistic effects on hydro-oil yield and quality. Experiments were carried out in a batch reactor under subcritical water conditions with varying biomass-to-plastic ratios and residence times. The co-HTL process exhibited enhanced hydro-oil yields compared to individual feedstocks, suggesting favorable interactions between biopolymer degradation intermediates and plastic-derived compounds. GC-MS and FT-IR analyses revealed that co-liquefaction produced hydro-oils with higher aliphatic content and reduced oxygenated species, improving the fuel-like properties. The findings demonstrate the potential of co-HTL as a sustainable valorization pathway for marine biomass and plastic waste, contributing to circular bioeconomy and waste-to-energy strategies.