Design and assessment of an innovative renewable energy system for waste management and environmental protection – Viona Group

This study presents the design and thermodynamic assessment of a novel waste-integrated multigeneration system that co-produces electricity, green hydrogen, freshwater, high-purity oxygen, and district heating by utilizing municipal wastewater sludge, wind energy, and thermal recovery. The proposed system is therefore modeled and analyzed through detailed mass, energy, and exergy balance equations. It achieves 42% energy efficiency and 52% exergy efficiency under steady-state conditions. Annually, the system generates approximately 14.21 kg-tonnes of hydrogen, 9.21 kg-tonnes of freshwater, and 113.68 kg-tonnes of oxygen, which is directly utilized in an integrated fish farming unit, enabling sustainable aquaculture. The system provides a net electricity generation of approximately 13 MW supplied to the grid. Additionally, 97.22 MW of recovered thermal energy is supplied as district heating, thereby supporting clean urban heat applications. Wind power and sludge-derived biogas provide renewable and continuous energy input, reducing fossil fuel dependence. By processing 23,352 m3/year of sludge, the system prevents methane emissions from uncontrolled anaerobic degradation and transforms organic waste into valuable outputs. Furthermore, the integration of electrification and electro-fuels pathways enhances the system's ability to convert renewable electricity and bio-derived intermediates into clean fuels, aligning with broader decarbonization strategies. These results highlight the system’s capacity to support circular economy principles while addressing the interconnected energy, water, food and environmental challenges in an integrated and efficient manner.