Valorization of Polypropylene Plastic Waste via Slow Pyrolysis: Pathways to Pyro-Oil Production

This research examines the pyrolysis of polypropylene (PP) plastic waste as a feasible method for pyro-oil generation. The primary objective is to convert non-biodegradable polymer waste into value-added liquid fuel while addressing environmental concerns associated with plastic pollution. The pyrolysis of PP was conducted in a batch reactor at regulated temperatures of 300, 350, and 400 °C with reaction times of 30, 60, and 90 minutes to examine the thermal degradation behavior, product distribution, and quality of the obtained pyro-oil. The highest pyro-oil yield of 68% was achieved at 400 °C, indicating optimal thermal cracking of polypropylene chains. Under these conditions, the pyro-oil exhibited a hydrocarbon content of 49.3%, emphasizing its viability as an alternative energy source. The calorific value of the pyro-oil ranged from 48 MJ kg⁻¹ to nearly 49 MJ kg⁻¹. The possible reaction pathways were determined in this study, as indicated by the pre-exponential factor and activation energy derived from the Arrhenius equation. These findings demonstrate the feasibility of valorizing polypropylene waste through slow pyrolysis, offering a promising pathway for resource recovery, circular economy implementation, and reduction of the environmental impact of plastic waste.