Energy, environment and economy assessment of medical waste disposal technologies in China.

Medical waste (MW) has exploded since the COVID-19 pandemic and aroused great concern to MW disposal. Meanwhile, the energy recovery for MW disposal is necessary due to high heat value of MW. Harmless disposal of MW with economically and environmentally sustainable technologies along with higher energy recovery is urgently required, and their energy recovery efficiencies and environmental impacts reduction due to energy recovery are key issues. In this study, five MW disposal technologies, i.e. rotary kiln incineration, pyrolysis incineration, plasma melting, steam sterilization and microwave sterilization, were evaluated and compared via energy recovery analysis (ERA), life cycle assessment (LCA), and life cycle costing (LCC) methods. Furthermore, three MW incineration technologies with further energy recovery and two sterilization followed by co-incineration technologies were analyzed to explore their improvement potential of energy recovery and environment benefits via scenario analysis. ERA results reveal that the energy recovery efficiencies of "steam and microwave sterilization + incineration" are the highest (≥83.4%), while that of the plasma melting is the lowest (19.2%). LCA results show that "microwave sterilization + landfill" outperforms others while the plasma melting exhibits the worst, electricity is the most significant contributor to the environmental impacts of five technologies. Scenario analysis shows that the overall environmental impact of all technologies reduced by at least 45% after further heat utilization. LCC results demonstrate that pyrolysis incineration delivers the lowest economic cost, while plasma melting is the highest. Co-incineration of sterilized MW and municipal solid waste could be recommended.