Thermodynamic and environmental analysis of self-thermal antibiotic residues supercritical water gasification system for hydrogen and power production

Abstract

Efficient treatment of antibiotic residue, containing a range of persistent organic compounds, is essential to ensure the protection of both the environment and human health. Supercritical water gasification technology could achieve the clean and efficient energy conversion of antibiotic residues. In this paper, a self-thermal supercritical water gasification system for antibiotic residues is developed to convert antibiotic residues to high-purity H2 and electrical power. The system analysis results demonstrate that increasing the antibiotic residue slurry concentration, elevating the gasification reactor temperature, and optimizing the ratio of water-to-dry antibiotic residues effectively enhance system efficiency and H2 yield within specific ranges. The H2 yield and net electrical power at optimal operating conditions are 634.52 kg/h and 2.3 MW with 10 t/h dry antibiotic residue feeding. Meanwhile, the energy efficiency, exergy efficiency, and cold gas efficiency of the system are 61.32%, 63.05%, and 53.96%, respectively. The life cycle assessment analysis shows that the global warming potential of the system is 20.77 kg CO2-eq/kg H2 with the above operating conditions. Taking into account the emission reduction impact of the system on thermal power generation, the inclusion of CO2 capture and storage units can potentially lead to a negative global warming potential for the system.