Mathematical modeling of a slurry bubble column reactor for hydrodesulfurization of diesel fuel: Single- and two-bubble configurations

•Mathematical model for HDS of diesel fuel in slurry bubble column reactor developed.•The transient mathematical model based upon single and two bubbles configuration.•DBT, BPH, CHB and BCH considered as the four main sulfur-contained reactants.•The modeling results revealed more than 98% of sulfur removal for the two models.•The effects of operating parameters including; T and sulfur conversion discussed. In this investigation, a mathematical model for HDS of diesel fuel in a slurry bubble column reactor was developed. The model is based on the axial dispersion of the heterogeneous gas flow regime, which includes two various bubble classes: large (20±70mm) and small (1±10mm). By assuming only large or large plus small bubbles in the column, single- and two-bubble class mode equations are developed. The developed models to solving the mass and enthalpy balances from which the sulfur conversion was obtained that undertaken. The chemical kinetics over NiMoS/γ-Al2O3 catalyst were undertaken for the reaction rate of the involved reactions. The reactor operating conditions including pressure of 50bar at a temperature of 350°C, inlet superficial gas velocity of 0.1ms−1, and liquid velocity of 0.005ms−1 were chosen. The obtained modeling results revealed 99.53% and 98.95% of sulfur removal for single- and two- bubble classes, respectively. Furthermore, the results of the two models compared satisfactorily with experimental data from open literature, and a collation utilizing empirical data between the two hydrodynamic models demonstrated that the two-bubble model was more compatible with the empirical data than the single-bubble model. The results of modeling including temperature variations, other reactor characteristics and conversion of desired product were discussed throughout in this research in detail.