Catalytic Pyrolysis of Polyethylene Waste: A Comparative Study of Thermal and Catalytic Degradation

The increasing accumulation of plastic waste is one of the major concerns in the contemporary world. India's estimated daily production of plastic waste in the fiscal year 2021-22 is around 26000 tons. The pyrolysis provides methods for the removal of this waste in a constructive manner by transforming it into a usable fuel. In this research work, the catalytic and non-catalytic pyrolysis of polyethylene (PE) waste was studied using magnesium carbonate (MgCO3) as a catalyst. The non-catalytic method yielded a wax fraction containing 60% (w/v) at 450℃ while the catalytic method gave 70% (w/v) clear brown liquid fraction. The properties of the liquid fractions were compared with international diesel fuel, showing several similarities with the exception of flashpoint. The GC-MS results indicate that the catalytic products had a liquid compound within the observable limits C10 to C15 which is comparable to diesel. The char from catalytic pyrolysis was better in terms of porosity revealed through SEM image analysis. XRD images confirmed that the activated char still contained some MgO catalyst, indicating some potential for catalyst recovery and reuse.