Hydrodenitrogenation and Hydrodesulfurization of Heavy Gas Oil Using NiMo/Al2O3 Catalyst Containing Boron: Experimental and Kinetic Studies

In this work, a systematic study has been conducted to optimize the process conditions and to evaluate kinetic parameters for hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) of heavy gas oil derived from Athabasca bitumen using NiMo/Al2O3 catalysts containing boron (B). In the catalyst, the concentrations of boron were varied from 0 to 1.7 wt %. Experiments were performed in a trickle-bed reactor at the temperatures, pressures, and liquid hourly space velocities (LHSVs) of 340-420 °C, 6.1-10.2 MPa, and 0.5-2 h^-1, respectively. H2 flow rate and catalyst weight were maintained constant at 50 mL/min and 4 g, respectively, in all cases. Statistical analysis of all experimental data was carried out using ANOVA to optimize the process conditions for HDN and HDS reactions. Kinetic studies for HDN and HDS reactions were studied within the temperature range of 340-400 °C using a power law model as well as the Langmuir-Hinshelwood model. The power law model showed that HDN of heavy gas oil follows first-order kinetics while the HDS process follows 1.5-order kinetics. The activation energies for HDN and HDS reactions from power law and LangmuirHinshelwood models were 75 and 87 kJ/mol and 110 and 159 kJ/mol, respectively.