Tuning High-Density Polyethylene Hydrocracking through Mordenite Zeolite Crystal Engineering
Pavel A. Kots, Panagiota A. Doika, Brandon C. Vance, Sean Najmi, Dionisios G. Vlachos
Abstract
We investigate the hydrocracking of high-density polyethylene using a bifunctional Pt/Al 2 O 3 and modified mordenite acid catalyst. Mass transport limitations impact polymer diffusion into the mordenite pore complex. Initial reaction intermediates are formed on the zeolite’s outer surface. Intercrystallite open-end mesopores improve the diffusion of reaction intermediates deeper into the crystal. Recrystallization and desilication of mordenite lead to a higher polymer conversion and shift the product distribution maximum from pentanes to hexanes and heptanes. The nature of mesopores (occluded or open) and total Brønsted acidity significantly impact zeolite activity and selectivity.