Thermal investigation of plastic solid waste pyrolysis via the deconvolution technique using the asymmetric double sigmoidal function: Determination of the kinetic triplet, thermodynamic parameters, thermal lifetime and pyrolytic oil composition for clean energy recovery

Abstract

Pyrolysis is widely used as a waste treatment technology (thermal recycling), which can be an alternative to disposal in landfills. To investigate the applicability of pyrolysis of plastic solid waste (PSW) to recovery energy from plastic solid waste (PSW), the pyrolysis of PSW was performed in a thermogravimetric analyzer under an inert condition. The PSW samples were heated under dynamic conditions from 25 °C to 1000 °C at four low heating rates (5, 10, 20, and 30 °C min−1). The decomposition behavior of pseudo-components was characterized by the deconvolution method using the asymmetric double sigmoidal function (Asym2Sig), and the data obtained were used to determine the kinetic parameters. The kinetic parameters were evaluated by isoconversional methods, the compensation effect factor and master plot. The thermodynamic parameters (ΔG, ΔH and ΔS) and lifetime were estimated based on the thermogravimetric and kinetic data. In addition, a fixed-bed reactor and GC–MS were employed to identify some valuable products in pyrolytic oil. Three pseudo-components were identified, which had the main influence on pyrolytic performance. The kinetic parameters suggested the suitability of PSW pyrolysis, where the reaction models were found to be suitable for describing the thermal behavior of PSW pyrolysis. The simulation profile curves from the simplified kinetic expression based on the kinetic triplet and deconvolution results had a satisfactory agreement with experimental conversion curves. The thermodynamic parameters were consistent with other wastes used as a bioenergy feedstock. Plastic solid waste presents attractive characteristics for pyrolytic oil production. The main highlights achieved for this study indicate that the pyrolysis of plastic solid waste can be an important step for the development of a recycling system that can recover energy from these wastes in a clean and environmentally friendly process.