Upgrading of plastic waste-derived gaseous hydrocarbon productions through combining steam gasification with Cu/Ni-MnCo2O4 spinel catalysts

Catalytic steam gasification is a promising route for converting plastic waste into valuable gaseous products. This work explores the heterogeneous catalytic gasification behavior of polystyrene (PS) in a two-stage fixed bed system, as well as the promotion mechanism for the generation of gaseous hydrocarbons. The obtained results indicate that adding MnCo 2 O 4 catalyst can effectively promote the formation of gaseous hydrocarbons. Further, the incorporation of Cu strengthens the above reaction process, resulting in a yield of 85.08 mmol/g for the C 1 -C 3 gaseous hydrocarbons. However, the doping of Ni has a negative effect on the generation of gaseous hydrocarbons. Moreover, an increase in the flow rate of steam within the system results in an initial rise followed by a decline in the yield of gaseous hydrocarbons. The optimal steam inflow is determined at 0.14 mL/min. The cycling test results of the catalyst show that the yield of the gaseous components of C 1 -C 3 can still be maintained at about 80 % of the initial state after five cycles. Finally, the synergistic pathway of steam and catalyst in PS gasification is elucidated. These works provide important and valuable guidance for the preparation of high-value gas-phase hydrocarbon products from waste plastics.