Influence of promoting Ni-based catalysts with ruthenium in the dry reforming of polypropylene plastics for syngas production

The catalytic dry reforming of plastic waste is conducted in two-stage fixed bed reactors. The pyrolysis of polypropylene plastics occurs in the first reactor, and the pyrolyzed gases undergo a reforming reaction with carbon dioxide over a catalyst in the second reactor. The wet impregnation method is used to synthesize Ru–Ni/Al₂O₃ catalysts, which are then calcined and reduced at 800 °C. The results show that as the nickel loading increases, the syngas production increases. Promoting the catalyst with a small quantity of ruthenium significantly improves the plastic conversion into syngas. The dry reforming of polypropylene over 1Ru15Ni/Al₂O₃ catalyst resulted in the maximum syngas yield (159 mmol_syngas/g_PP) at a 2:1 plastic to catalyst ratio. The catalytic dry reforming of plastics is promising for the production of synthesis gas.