Low-Temperature Upcycling of Polyethylene into Fuel-Range Hydrocarbons: An Innovative Approach on the Feed-Catalyst Bed Design

The energy-intensive nature of the catalytic pyrolysis of plastic for fuel production remains a major challenge in the renewable energy field. To address this, the feed-catalyst bed of a vertical tubular pyrolysis reactor was optimized to upcycle polyethylene (PE) into fuel-range hydrocarbons. Using a dual-stage feed-catalyst bed design (feed-to-catalyst ratio of 5:1), 86.1 wt % conversion of PE was achieved at 300 °C. Compared to the single-stage design, this design improved conversion by 1.68-fold, attributed to the sequential cracking effect. This effect was amplified when a set of zeolites with a 12-membered ring (faujasite and mordenite) was incorporated, achieving a gasoline selectivity of 55.9%. The enhanced performance demonstrates that the dual-stage catalyst bed offers a promising design strategy for enabling low-temperature plastic upcycling with potential applications in renewable carbon resources.