Comparative Studies of the Effect of CaO and Zeolite Catalyst on Waste Plastics Pyrolysis

Abstract

The study examines the comparative studies of the effect of calcium oxide (CaO) and zeolite catalyst on waste plastic pyrolysis. The primary objectives of the study are characterization of CaO and zeolite catalyst using XRF and XRD, waste plastic pyrolysis using CaO and zeolite catalyst, and optimization of the parameters of pyrolysis using CaO and zeolite catalyst. The ERD and XRF analysis shows that the crystal structure of zeolite corresponds to those of ZSM-5 a silica to alumina ratio of 29.48 while the CaO catalyst contains mainly CaO in its crystal structure with 98.848% CaO. The waste plastic pyrolysis was successfully carried out. The optimization study shows that the optimum values of pyrolysis temperature, heating rate and catalyst type for maximum oil yield are 597 o C temperature and 29.909 o C/min heating rate using zeolite catalyst type to give a maximum waste plastic pyrolysis oil yield of 58.385% while 600 o C and 30 oC/min using CaO catalyst type give a yield of 54.868% which shows that the yield obtained with CaO as catalyst is relatively comparable to that obtained using zeolite. The study also shows that there was no much significant difference in the yield of CaO and zeolite at the established optimum condition for both catalyst type. Therefore, considering cost of zeolite CaO could be useful as catalyst for waste plastic pyrolysis.