A mathematical model based on power law kinetics was selected to simulate the hydrotreating process of diesel fuel (also called diesel oil or diesel), assuming hydrogenation reactions of sulfur compounds, nitrogen compounds, aromatic compounds, and olefins. The process efficiency depended on the diesel flow rate, catalyst volume, hydrogenation reaction rate constants, and reaction orders. The reaction rate constants were expressed as functions of the mean temperature in the catalyst bed using the Arrhenius equation. The parameters of the Arrhenius equation for the hydrogenation of sulfur and nitrogen compounds, i.e., the pre-exponential factors (6.515–15.62·10⁴ h⁻¹) and activation energies (47.24–66.13 kJ/mol), were estimated based on monitoring data obtained in an industrial plant. The results obtained suggested that the catalyst used in the industrial reactor had almost equal specificity for the hydrogenation of sulfur and nitrogen compounds.