Catalytic hydrocracking of heavy wax from pyrolysis of plastic wastes using Pd/Hβ for naphtha-ranged hydrocarbon production

The catalytic hydrocracking of heavy wax derived from the pyrolysis of waste plastics was conducted for valuable naphtha production on the bifunctional catalyst. As the result of the support screening to prepare the bifunctional catalyst, the acidic Hβ was chosen, which exhibited the reasonable wax conversion (64%) and the highest saturated and unsaturated hydrocarbon content (98%) in naphtha fraction at 380 ̊C. Then, Pd was impregnated on the Hβ as an active metal, and ≥ 0.6% Pd could dramatically improve the cracking and hydrogenation activities of the Hβ even at 360 ̊C from 47.9% to >97.5% conversion. Also, the liquid product mainly composed of saturated hydrocarbons (88% paraffins), which is quite suitable for naphtha. Especially, Pd[0.6]/Hβ, having 0.012 of the metal/acids ratio, exhibited the highest hydrocracking activity (99.2% conversion and 97.8% naphtha fraction in liquid), and that of >0.012 led catalyst’s isomerization activity increased. [Display omitted] •The production of naphtha from the heavy wax from the pyrolysis of waste plastics.•The catalytic hydrocracking of heavy wax over bifunctional Pd/Hβ.•Highly enhanced cracking and hydrogenation activities by Pd impregnation on Hβ.•The ratio of metal/acid sites of catalyst would be preferred to 0.012 for cracking.