Suitable properties of the HY zeolite of NiW/HY catalysts for the hydroprocessing of a plastic pyrolysis oil/vacuum gas oil (PPO/VGO) blend

The possibility of using oil refinery facilities for treating streams derived from consumers’ society wastes, such as plastics, is gaining relevance in recent times. This strategy would cover two goals at the same time: (i) improve the management of wastes reducing the landfilling and incineration rates, and (ii) integrate the conventional oil industry within the circular economy. In this context, the hydroprocessing of plastic pyrolysis oil (PPO) blended (10 wt%) with vacuum gas oil (VGO) was investigated. In particular, four different NiW/HY catalysts were prepared and the influence of HY zeolite with different SiO 2 /Al 2 O 3 molar ratios (80, 30, 12, and 5.1) for producing automotive fuel-like fractions was studied. The catalysts were characterized in detail by several techniques to correlate their performance with their main physico-chemical characteristics. The hydroprocessing runs were conducted in a batch reactor with continuous H 2 feeding at 80 bar, 420 °C, catalyst-to-feed (C/F) mass ratio of 0.1 g catalyst g feed −1 and for 2 h long. Results exposed high differences in product distribution and composition. Overall, it was obtained that highly acidic catalysts with a high concentration of Brønsted-type acid sites with moderate acidic strength rule the process, but these acidic properties must be endorsed by adequate textural properties in a matter of high specific surface and wide pore sizes. According to this, the NiW/HY 12 catalyst offered the best performance, since the highest hydrocracking conversion and sulfur removal were achieved while the production of naphtha and light cycle oil fractions was maximized. The higher hydrodearomatization and hydroisomerization activity of the NiW/HY 30 catalyst made them appropriate to produce highly iso-paraffinic and poorly aromatic gasoline and LCO fractions. • The hydroprocessing of a plastic pyrolysis oil/vacuum gasoil blend was studied. • NiW/HY catalysts with different SiO 2 /Al 2 O 3 ratios were tested. • Acidic catalysts with moderate strength and predominance of Brønsted sites stood out. • Wide pore sizes in the catalysts were also required for hydroprocessing the blend.