Catalytic Cracking of Crude Waste Plastic Pyrolysis Oil for Enhanced Light Olefin Production in a Pilot-Scale Circulating Fluidized Bed Reactor

Energy-efficient processes using sustainable resources, such as plastic waste, are essential for alleviating environmental pollution and carbon emissions. Herein, we demonstrated the highly efficient direct conversion of crude waste plastic pyrolysis oil (WPPO) into light olefins using a pilot-scale circulating fluidized bed reactor (CFBR) with a WPPO throughput of 1000 g·h–1. Catalytic WPPO cracking over a microspherical P-modified steam-treated ZSM-5 catalyst outperformed naphtha cracking in terms of the C2–C4 olefins yield (44.1 vs 34.6 wt %), highlighting the superiority of WPPO as a feedstock for light olefin production. Fine-tuning the operating parameters, including the catalyst circulation rate (24,000 g·h–1), feed rate (1000 g·h–1), and catalyst-to-oil ratio (24) further increased the C2–C4 olefins yield to 46.2 wt %. Main product yields were stable during a 24 h durability test, with average ethylene, propylene, C4 olefins, and C2–C4 olefins yields of 10.3, 21.4, 12.6, and 44.3 wt %, respectively, indicating the suitability of the CFBR for continuous catalytic WPPO cracking. This approach offers advantages over commercial schemes, including complete utilization of crude WPPO, increased C2–C4 olefins yield, reduced energy consumption, continuous coke removal, and non-necessity of hydroprocessing, making it a promising alternative for sustainable light olefin production with environmental benefits.