Commercial Fluid Catalytic Cracking Catalysts for Polymers Chemical Recycling

Commercial FCC catalysts (fresh and equilibrated) and laboratory made catalysts from Y type zeolite and γ‐Al 2 O 3 are characterized by standard techniques and evaluated in the cracking of pure PP, LDPE, and PS polymers as well as coprocessing PP/LDPE mixture in TGA (light‐off curves) and a unique operando FTIR & GC‐MS set‐up. Conversions, products selectivities as well as coke deposition and removal are studied as a function of temperature. In spectroscopic operando investigations, MCR‐ALS analysis provides significant insight into the observed results. The equilibrium FCC catalyst (Cat‐Eq800) differs markedly from its fresh counterpart (Cat‐F800) in product selectivity. Regardless of the polyolefin feed, Cat‐Eq800 exhibits higher olefinicity in the C 4 fraction. In both commercial catalysts, coke precursor formation proceeds predominantly via paraffin consumption. In situ FTIR analysis revealed valuable information regarding reactant diffusion and catalyst acidity. Despite undergoing severe deactivation treatments, the equilibrium catalyst displays the highest Brønsted‐to‐Lewis acid site ratio while maintaining efficient mass transport through its hierarchical pore structure. Important information to better design FCC catalysts can be derived, as the exact composition of these important catalysts are often tailored for specific families of heavy oil fractions.