Optimization of pyrolysis process parameters for a higher yield of plastic oil with enhanced physicochemical properties derived from medical plastic wastes

Abstract

After the COVID-19 pandemic, the demand for personal protective equipment (PPE) kits has increased substantially to ensure workplace health. As the majority of PPE kits are derived from plastic, the disposal of used PPE kits poses a significant risk to the environment and human health. Though some existing studies addressed the conversion of medical wastes into useful energy, none of the studies attempted to optimize the pyrolysis process parameters for a higher yield of pyrolysis oil extraction with improved physicochemical properties. Hence, in the present study, waste plastic oil (WPO) from PPE gowns was extracted using a pyrolysis process for engine applications to protect the environment and promote greener recycling. The pyrolysis process parameters such as reaction temperature (RTemp), reaction time (RTime), and catalyst concentration (CC) were optimized using a multi-response optimization tool for a higher yield of WPO with improved physicochemical qualities. The physicochemical properties of optimally produced WPO were compared with those of regular diesel (RD), and the elemental and functional groups were analyzed. The optimization result indicates that a RTemp of 403.2 °C, a RTime of 105.6 min, and a CC of 1.3 wt% produce the highest yield of WPO (81.2%) with exceptional physicochemical properties. The robustness of the proposed model was demonstrated by the confirmation experiment that validated the predicted output response values. Under optimal conditions, the physicochemical properties of derived WPO are comparable to those of RD, and the WPO's functional compounds assure its viability as a diesel fuel substitute.