Upgrading Siberian (Russia) crude oil by hydrodesulfurization: Kinetic parameter estimation in a trickle-bed reactor

Hydrodesulfurization (HDS) of sour crude oil is an effective way to address the corrosion problems in refineries and is an economic way to process sour crude oil in an existing refinery built for sweet oil. Siberian crude oil transported through the Russia-China pipeline could be greatly sweetened and could be refined directly in local refinery designed for Daqing crude oil after the effective HDS treatment. In this study, the HDS of Siberian crude oil was carried out in a continuous flow isothermal trickle-bed reactor over Ni-Mo/γ-Al₂O₃. The effects of temperature, pressure and LHSV were investigated in the ranges of 320-360 ℃, 3-5 MPa and 0.5-2 h^-1, keeping constant hydrogen to oil ratio at 600 L·L^-1. The HDS conversion could be up to 92.89% at the temperature of 360 ℃, pressure of 5 MPa, and LHSV of 0.5 h^-1, which is sufficient for local refineries (> 84%). A three phase heterogeneous model was established to analyze the performance of the trickle-bed reactor based on the two-film theory using Langmuir-Hinshelwood mechanism. The order of sulfur component is estimated as 1.28, and the order of hydrogen is 0.39. By simulating the reactor using the established model, the concentration of H₂, H₂S and sulfur along the catalyst bed is discussed. The model is significantly useful for industrial application with respect to reactor analysis, optimization and reactor design, and can provide further insight of the HDS of Siberian crude oil.