Mathematical Modeling and Kinetic Study of Deep Hydrodesfulfurization of Dibenzothiophenes Using CoMoP/Al2O3 Catalyst

Deep hydrodesulfurization (HDS) is a highly effective process for removing sulfur from petroleum and its derivatives, achieving ultra-low sulfur levels, improving fuel quality, and reducing air pollution. This study estimates kinetic parameters for the HDS process using experimental data for dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) on a CoMoP/Al₂O₃ catalyst in a fixed-bed reactor. A global power-law model provided the best fit for each dataset (R² > 0.99), while a single individual model was suitable across all data. The estimated reaction order concerning hydrogen was 0 for DBT and 1 for 4,6-DMDBT. Pre-exponential Arrhenius constants and activation energies (ranging from 90–100 kJ/mol) were also estimated and can be applied to reactor design and process optimization in HDS systems.