Conversion of pyrolysis vapors derived from non-biodegradable waste plastics (PET) into valuable fuels using nickel-impregnated HZSM5-70 catalysts

• NiO/HZSM5-70 catalyst for reforming of PET pyrolysis oil into value-added fuels. • The catalysts exhibited good performance in the reduction of oxygenated compounds. • NiO/HZSM5-70 resulted in high selectivity of gasoline (C 5 -C 12 ) hydrocarbon. • Increasing the impregnation loading and temperature favored to generate alkenes. • The regenerated catalyst performed well in recyclability in the reforming process. Recycling waste plastics into pyrolytic fuels is a highly promising energy-saving approach. The improvement and enhancement of the resulting fuel quality from heavy oil-derived-waste plastics pyrolysis is in high demand. We performed catalytic reforming of heavy oils-derived polyethylene terephthalate (PET) pyrolysis to simultaneously improve the quality of oils into valuable fuels (gasoline-range hydrocarbon) and reduce the oxygenated compounds. Nickel-impregnated HZSM5-70 catalysts were prepared by the wet-impregnation method. The catalytic process was carried out in a catalytic tubular reactor at a constant feeding rate of 2.5 mL/h. In particular, various processing factors were examined by varying the impregnation loading of nickel (2–10 wt%), catalyst mass (1–5 wt%), and process temperature (400–500 °C). Increasing any of the three process parameters resulted in a relatively similar decrease in the quantity of liquid products and an improvement in the quality of reformed products. The best quality of reformed oils were obtained at 5 % catalyst loading and 10 % nickel loading on the catalyst at 450 °C. FT-IR analyses show that raising process parameters has a substantial influence on increasing aliphatic and aromatic hydrocarbon content, while lowering the quantity of undesired products (acids, alcohols, and ketones) in the oils. GC–MS analysis results confirmed that the relative content/area of liquid products predominantly contains gasoline-range hydrocarbons (C 5 -C 12 ), with a total of 33.39 % on blank-run. The hydrocarbons (C 5 -C 12 ) production from HZSM5-70 and NiO/HZSM5-70 was greatly enhanced to 66.48 % and 85.05 %, repectively, while the oxygenated compounds, including alcohols, acids, and ketones were reduced from 39.38 to 10.75 % (total area). In comparison to HZSM5-70, the NiO/HZSM5-70 catalyst performs more effectively, retaining its catalytic activity after five cycles (∼3 % decrease). Thus, the NiO/HZSM5-70 exhibits high catalytic performance and reusability.