Comparison of kinetic and reactor models to simulate a trickle-bed bench-scale reactor for hydrodesulfurization of VGO

One dimensional homogeneous and heterogeneous reactor models and nth-order and two-parallel reactions following first order kinetics were explored in order to compare their capabilities to predict the sulfur content in the liquid product coming from a trickle-bed bench-scale reactor, where hydrodesulfurization of vacuum gas oil took place. Experimental data of sulfur concentration obtained at T = 340–380 °C, P = 5.3 MPa, LHSV = 1.0–3.0 h−1 and hydrogen-to-oil ratio of 356 m3/m3 were used to derive kinetic and related parameters. All proposed models showed accurate predictions being the pseudohomogeneous reactor model with two-parallel reactions kinetics the best one to simulate the bench-scale reactor in terms of minimal differences between the experimental and calculated sulfur concentration. Implications of using the different models are briefly discussed in order to evaluate their pertinence depending on the required level of detail and data available to describe the HDS process.