Hydrocracking of surgical face masks over Y Zeolites: Catalyst development, process design and life cycle assessment

Abstract

This study highlights the hydrocracking route for the management of surgical face masks, made of polypropylene, into liquid fuels. Hydrocracking experiments were performed at 325 ℃ and 10 bar cold H2 pressure over Ni-loaded HY and steamed HY zeolites. Ni-loaded steamed Y zeolite demonstrated to be the best catalyst leading to considerably high conversion (100 wt%) and selectivity to liquids (85.5 wt%). The increase in the external surface area and mesoporous volume that improved the bulk polymer molecules diffusion, combined with the uniformly dispersed Ni particles and the additionally generated Lewis acidity, were at the origin of the observed behaviour. This catalyst also showed reasonable stability and ability to be thermally regenerated. From the environmental perspective, life cycle assessment shows the benefits of hydrocracking over pyrolysis and incineration.Therefore, our results demonstrate that Ni-loaded steamed Y zeolites could be promising catalysts for the upcycling of surgical face masks to gasoline range fuels, with minimum environmental impacts.