Catalytic pyrolysis of four different plastic waste: Pilot-scale conversion, product characterization, and life cycle assessment

• Catalytic pyrolysis of different multi-layer plastics were studied. • Polyethylene Terephthalate and multilayer plastics favored increased gas formation. • PET plastics produced high-quality oils dominated by C 1 –C 10 fractions (56–64%), suitable for gasoline applications • Life Cycle Assessment (LCA) results revealed that catalytic pyrolysis reduced Global Warming and Acidification Potential. This study investigates the catalytic pyrolysis of four different plastic wastes, namely, Polyethylene Terephthalate (PET), biaxially oriented polypropylene (BOPP), metallized PET (MET/PET), and metallized BOPP (BOPP/MET) was systematically investigated in a pilot-scale packed-bed reactor operated in batch mode. The reactions were performed without catalysts and using two different catalysts, namely, ZSM-5 and zeolite. Catalytic pyrolysis increased liquid pyrolysis oil production and promoted deoxygenation, particularly for polyolefin-rich feedstocks. Also, GC-MS and FT–IR analyses confirmed that PET and metallized PET (MET/PET) produced high-quality hydrocarbon oils dominated by C 1 –C 10 fractions (56–64%), suitable for gasoline applications, with reduced oxygenate content (∼13–14%). Catalytic pyrolysis greatly improved liquid oil yield, and zeolite had a maximum yield of 46.67 %wt, whereas ZSM-5 catalysis favored more gas production through secondary cracking reactions. GC-MS results showed that hydrocarbon-rich oils containing C 1 -C 10 fractions (56-64%) with reduced oxygenates were produced. Catalytic pyrolysis significantly improved liquid oil yield, with zeolite achieving a maximum of 46.67 wt.%, while ZSM-5 favored gas formation. BET analysis showed a higher surface area for zeolite (297.44 m 2 /g) compared to ZSM-5 (188.97 m 2 /g), correlating with enhanced catalytic performance. Life Cycle Assessment (LCA) results revealed that zeolite catalyst substantially reduced Global Warming Potential, Acidification Potential, and Eutrophication Potential compared to non-catalytic processes. Additionally, the lowest environmental impact was observed for the pyrolysis conversion of biaxially oriented polypropylene (BOPP) feedstock with zeolite catalyst. The results demonstrate that catalytic pyrolysis enables efficient conversion of non-recyclable plastic waste into low-oxygenate liquid fuels, while also recovering carbon-rich char. This process provides a sustainable thermochemical route toward circular economy-based plastic waste management. Polyethylene Terephthalate and multilayer plastics favored increased gas and char formation.