Life cycle assessment of integrated hydrothermal liquefication of food waste with biological process toward bio-oil production

This study evaluated the environmental impact of three food waste hydrothermal liquefaction (HTL) scenarios integrated with bio-processing units. Scenario 2, which involved dark fermentation followed by HTL, produced the highest bio-oil yield and quality but also had the greatest environmental impact due to increased carbon emissions. Scenario 3, which combined HTL with anaerobic digestion, showed the most favorable environmental outcomes by effectively treating wastewater and generating biogas, making it the most sustainable option. Scenario 1, involving only HTL and wastewater treatment, had a lower environmental impact but yielded lower-quality bio-oil. Overall, scenario 3 is recommended for its balance between environmental sustainability and resource efficiency.