Thermo-kinetic Investigation of Polyethylene Terephthalate (PET) Plastic Waste Catalytic Pyrolysis over Biomass Fly Ash (BFA) /

Abstract

Plastic waste stands as the most alarming challenge for environmental and human health, which needs to find some techniques to use for energy recovery. This investigation evaluates the plastic waste material polyethylene terephthalate (PET) through GCV, RAMAN, FTIR, and XRD, and the catalyst biomass fly ash (BFA) is characterized via XRD, FTIR, and TGA. The pyrolysis at a heating rate of 5,10,15 and 20 ºC/min is carried out in a thermogravimetric analyzer (TGA), the only catalytic PET blend i.e. 10 wt.% BFA PET which showed a major shift in the peak temperature for the pure PET catalytic blends along with the increment in the weight loss, which will consider as an optimum catalytic blend. The thermo-kinetic study is performed by using twelve (12) mechanisms of model fitting (coats-Redfern method), and model free (Friedman, KAS, FWO) to find activation energy (Ea) based on regression factor (R2 ). The activation energy (Ea) for pyrolysis of Pure PET is 200-220 kJ/mol and after catalyst loading it lies in the range of 140-200 kJ/mol and the same trend follows for change in enthalpy (∆H), the change in Gibbs free energy (∆G) and the change in entropy (∆S) decreases as the catalyst ratio increases. The catalytic blend 10 wt.% BFA-PET lower the values for Ea, ΔH, ΔG, and ΔS of the pure PET indicates the reaction reaching equilibrium at a slow pace. Reactivity analysis for 10 wt.% BFA-PET considering mean reactivity (Rm) and pyrolysis factor (Pf) are 38.7563 and 0.8517 respectively. The catalytic pyrolysis of PET has been proposed as a viable alternative for energy sources and its kinetics study is important for important for design an efficient large-scale reactor system.