Performances of Co−W/γ-Al2O3 Catalysts on Hydrotreatment of Light Gas Oil Derived from Athabasca Bitumen

γ-Al2O3-supported Co−W-based catalysts with varying cobalt (1−3 wt %) and tungsten (7−13 wt %) loadings were prepared using impregnation and sonochemical methods. Brunauer−Emmett−Teller (BET) analysis indicated that the sonochemical method of preparation resulted a larger reduction in surface area of the γ-Al2O3 support than the impregnation method for all the prepared catalysts. X-ray photoelectron spectroscopy (XPS) showed that most of tungsten metal segregated on the support surface of sonochemically prepared catalysts, whereas catalysts prepared via the impregnation method showed uniform metal dispersion on the support. The performances of all the synthesized catalysts were tested at a pressure of 8.9 MPa, a liquid hourly space velocity (LHSV) of 2 h-1, and temperatures of 340, 350, and 360 °C in a trickle-bed microreactor for the hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of light gas oil (LGO) derived from Athabasca bitumen. The initial screening tests indicated that an impregnated catalyst with 3 wt % cobalt and 10 wt % tungsten and a sonochemical catalyst with 3 wt % cobalt and 13 wt % tungsten are the most active catalysts for the HDN and HDS of LGO. These two catalysts were selected for detail performance, optimization, and kinetic studies. The effects of reaction temperature (340−380 °C), pressure (7.6−10.3 MPa), LHSV (1.5−2.0 h-1), and H2/gas oil ratio (400−800 mL/mL) were examined in the HDS and HDN of LGO with these catalysts. The impregnated catalyst showed higher nitrogen and sulfur conversion than the sonochemical catalyst under all reaction conditions. The reaction kinetics for HDS was best-fitted with a power-law model, whereas the same for HDN was determined to be best represented by a Langmuir−Hinshelwood model with a reasonable accuracy (0.90