Conversion of medical waste into value-added products using a novel integrated system with tail gas treatment: Process design, optimization, and thermodynamic analysis

The COVID-19 pandemic has generated substantial medical waste (MW), posing risks to society. Based on widespread MW incineration, this study proposes an integrated system with tail gas treatment to convert MW into value-added products with nearly zero emissions. Herein, steam generators and supercritical CO2 cycles were used to recover energy from MW to produce high-temperature/pressure steam and electricity. A simple power generation cycle achieved a net electricity efficiency of 22.4% through optimization. Thermodynamic analysis revealed that the most energy and exergy loss occurred in incineration. Furthermore, a pressurized reactive distillation column purified the resultant tail gas. The effects of inlet temperature, pressure, liquid/gas ratio, and recycle ratio on the removal and conversion efficiencies of NO2 and SO2 were evaluated. Nearly 100% of the SO2 and 75% of the NO2 generated by the incineration of MW have been converted into their acid forms. Based on the proposed tail gas treatment unit, high-purity CO2 (similar to 98% purity) was finally obtained.

Automated summary

The study proposes an integrated system to convert medical waste into value-added products with almost zero emissions through tail gas treatment. Energy from medical waste is recovered using steam generators and supercritical CO2 cycles to produce high-temperature/pressure steam and electricity. A simple power generation cycle achieves a net electricity efficiency of 22.4% through optimization. The proposed system also includes a pressurized reactive distillation column to purify the resultant tail gas, converting nearly 100% of SO2 and 75% of NO2 into their acid forms.