Experimental and Kinetic Studies of Aromatic Hydrogenation, Hydrodesulfurization, and Hydrodenitrogenation of Light Gas Oils Derived from Athabasca Bitumen

In this work, a systematic experimental and kinetic study of hydroprocessing of light gas oils (LGOs) such as vacuum LGO (VLGO), atmospheric LGO (ALGO), and hydrotreated LGO (HLGO) using NiW/Al 2 O 3 and commercial NiMo/Al 2 O 3 catalysts has been conducted. Experiments were performed by varying temperature from 340 to 390 °C, at a constant pressure and liquid hourly space velocity of 11.0 MPa and 0.6 h -1, respectively. H 2 /feed ratio was maintained at 550 mL/mL throughout the experiments. Appreciable hydrogenation of aromatics (AHYD) was achieved by the NiW/Al 2 O 3 catalyst at low temperatures and at high severities of hydrotreating. However, the hydrogenation activity of NiMo/Al 2 O 3 was superior to that of the NiW/Al 2 O 3 catalyst. For hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities, higher conversions of 95−98.8 and 96−99 wt %, respectively, were attained for the commercial NiMo/Al 2 O 3 catalyst throughout the temperature range studied. Simulated distillation of the feed showed that VLGO contained the most complex and heaviest compounds followed by HLGO and ALGO. Diesel selectivity in both ALGO and HLGO increased with hydrotreating temperature, but in the case of VLGO, it decreased with temperature. Kinetics studies showed that dearomatization of the HLGO feed was the most difficult, followed by ALGO and then the VLGO. Kinetics of ALGO and VLGO were best described by a pseudo-first-order reaction mechanism while the 1.3 power law kinetics worked well with HLGO.