Experimental Study on the Catalytic Pyrolysis of Low-Density Polyethylene (LDPE) over Phosphoric Acid–Activated Porous Carbon for Jet Fuel Production

This study aims to achieve the high-value utilization of waste plastics via catalytic pyrolysis by developing a biomass-derived porous carbon catalyst prepared from corn cob through phosphoric acid activation, which enables the targeted conversion of low-density polyethylene (LDPE) into hydrocarbons within the jet fuel range. A series of catalysts with distinct pore structures and surface acid properties were obtained by systematically regulating preparation parameters, including carbonization temperature and phosphoric acid impregnation ratio. The catalytic performance was evaluated in a fixed-bed reactor, and the effects of preparation conditions and reaction parameters on the distribution of gaseous, liquid, and solid products, as well as on liquid product selectivity, were systematically investigated. The results reveal a pronounced synergistic effect between the pore structure and acid properties of the catalyst, among which BDAPC-600-0.6, featuring a high acid density, abundant medium-strength acid sites, and a micropore fraction of approximately 40%, exhibits the best catalytic performance.This established a clear structure-activity relationship linking synthesis, structure, and performance. Under the optimized conditions of a pyrolysis temperature of 480 °C and a catalyst-to-feed mass ratio of 1, a liquid yield of 67.1 wt % was achieved, with the selectivity toward the target C8–C16 alkanes reaching up to 61.4 area %, while the selectivity toward