Optimizing the conversion of waste plastic into suitable engine fuel through response surface methodology

Abstract

The extensive utilization of plastic in daily life has significantly contributed to per-day waste generation. The conversion of waste plastic through pyrolysis into fossil fuel is a promising solution to waste management and energy crises. The precise control of the process parameters in the pyrolysis would be a sustainable business model. Since the optimization of process parameters for production yield and the physicochemical properties of waste plastic oil have been underexplored. So, the current research optimized input process parameters of pyrolysis through response surface methodology using a central composite design. The input parameters of the experimental design were reaction temperature (350°C-550°C), retention time (60–300 min), nitrogen flow rate (0–40 ml/s), and ZSM-5 catalyst concentration (1–5 wt%). Waste plastic is converted into the optimized yield of oil (85 %), solid (3 %), and syngas (12 %). Waste plastic oil (WPO) had optimal results of physicochemical properties like heating value (48 MJ/kg), flash point (60 °C), kinematic viscosity (2.1 mm²/s), and density (820 kg/m³). American Society for Testing and Materials Standards validated the produced WPO, which had better fuel properties than petroleum diesel. However, the application of other sustainable biocatalysts and uncondensed gas may be explored in future research.