Experimental Comparison of Catalytic and Non-Catalytic Pyrolysis of Mixed Plastic Waste for Enhanced Pyrolysis Oil Production in a Fixed-Bed Reactor

Abstract

The increasing generation of mixed plastic waste (MPW) has become a major environmental challenge due to inadequate waste management practices and the non-biodegradable nature of plastics. This study experimentally investigated the performance of catalytic and non-catalytic pyrolysis for converting mixed plastic waste collected from Agbor Town, Delta State, Nigeria, into liquid hydrocarbon fuel using a laboratory scale fixed bed reactor. The feedstock, comprising PET, HDPE, PVC, LDPE, PP, PS, and other post-consumer plastics, was characterized through proximate and ultimate analyses before pyrolysis. The results revealed low moisture (0.215%) and ash (0.212%) contents, high volatile matter (98.35%), and high carbon content (82.86%), indicating excellent fuel potential. Comparative experiments demonstrated that catalyst-assisted pyrolysis consistently enhanced pyrolysis oil production, yielding a mean oil output of 2.552 kg compared with 2.408 kg for non-catalytic pyrolysis. This result represents an average improvement of 5.98%. The catalyst also increased the maximum oil yield from 4.16 to 4.98 kg and exhibited greater effectiveness at higher feedstock loadings. These findings demonstrate that catalytic pyrolysis is an efficient and sustainable waste to energy technology. Besides, catalytic pyrolysis can improve pyrolysis oil recovery, thereby reduce environmental pollution, and promote circular economy principles for effective municipal plastic waste management in developing countries.