Pyrolysis kinetics of polyethylene terephthalate (PET) plastic bottle waste with coal fly ash zeolite

The PET bottle waste consists of PET bottle and PP plug. We investigated the catalytic pyrolysis kinetics of PET bottle waste using HY-FAZ obtained by activating CFA with acid and alkali. The catalytic effect of coal fly ash was investigated by thermal analysis of PET bottle waste with and without HY-FAZ of 20%, respectively, and comparison of degree of decomposition. Pyrolysis occurred in a temperature range of 623–753 K, and it was confirmed that HY-FAZ accelerated the pyrolysis process of waste, increasing the yield of volatile gas by 14.2% and decreasing the yield of solid residue by 14.14%. The pyrolysis with the HY-FAZ was characterized using TG and DTG in a temperature range of 313–923 K in N₂ atmosphere at four different heating rates (5, 10, 15 and 20 K·min⁻¹). The pyrolysis kinetics was investigated with five methods (FR, FWO, KAS, STK and DAEM). The pyrolysis reaction of PET bottle waste with HY-FAZ catalyst was carried out in two stages, the activation energies (E_a) of which were 177.3 kJ·mol⁻¹ and 182.9 kJ·mol⁻¹, respectively.