Optimizing advanced oxidative liquefaction of municipal solid waste and personal protective equipment of medical sector for solid reduction and secondary compounds production

Escalating proportion of polymer waste from medical sector (personal protective equipment (PPEs)) and increasing concentration of municipal solid waste (MSW) need to be recycled effectively to ensure sustainable waste management. The current research entails a comparative analysis of a novel oxidative liquefaction technique to disintegrate organic fraction of MSW and PPEs into oxygenated chemical compounds (OCCs) having secondary applications in chemical industry. When examined through ultimate and proximate analysis PPEs and MSW samples have a carbon content of 80.13 ± 2.34 % & 50.30 ± 0.50 % respectively sufficiently higher for secondary compounds production. The oxidative liquefaction process of selected wastes is performed through a meticulously organized experimental framework that integrates Central Composite Design with Fractional Factorial Design employing three critical parameters: 200–300 °C of temperature, 30–60 % of oxidant concentration, and 3–7 % waste-to-liquid ratio. An inverse analysis of the process heating behavior was performed to identify the temperature span over which major degradation of organic matrix occurs and specify exothermic or endothermic nature of various halves of reaction. At the end of the experiments, the total solid reduction (TSR) was in the range of 50–95 % for MSW and (45–97 %) for PPEs, supporting the process efficacy. Gas chromatography with flame ionization detection (GC-FID) was employed to identify the various liquid chemical fractions, and oxygenated chemical compounds (OCCs) yield was in the range of 13–51 g/kg MSW and 37–212 g/kg PPEs. Energy consumed during the process is monitored for both MSW and PPE samples and recorded from 0.7 to 1.4 kWh. Based on the obtained results employing one-way analysis of variance (ANOVA), detailed optimization of the experimental plan was carried out to obtain the most optimal values of the tested parameters that result maximum TSR and OCCs against the minimum resource consumption to support the industrialization of the suggested process.