Thermo-catalytic degradation of different consumer plastic wastes by zeolite a catalyst: A kinetic approach

Abstract

This research work includes the effect of Zeolite-A catalyst on the thermal degradation behavior of six different consumer plastic wastes like high density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET), polymethylene methacralate (PMMA), polystyrene (PS) and polytetrafluoro ethylene (PTFE) through kinetic approach by using thermogravimetric analysis (TGA) data. Kinetic parameters such as reaction order, activation energy, and Arrhenius constant for the degradation of different waste plastics is determined using model fitting Coats–Redfern method. All the plastics show one-step degradation in the temperature range of 300–600°C. There is a significant decrease in activation energy (E_a) for the thermo-catalytic decomposition of the plastics in presence of Zeolite A catalyst. The extent of catalytic effect is found different for different plastics in the order of HDPE < PP < PS < PET < PMMA < PTFE. The order of the thermal degradation reaction is also found different for different types of plastics. The order of the reaction is altered in case of PET, PS and PTFE in presence of the catalyst but it is unaffected in case of remaining plastics. This treatment would reduce the energy consumption of pyrolysis process and also make the process economical viable.