Reaction Performance Simulation Of Hydrodesulfurization Process In Monolithic Reactors

As a kind of important liquid fuel, diesel is the main source of sulfur dioxide in air. As people’s requirements increase quickly on the environment quality, it is urgently to reduce the sulphur in diesel and the hydrodesulphurization is an important way to realize it. Monolithic reactor is a new kind of reactors; it has low pressure drop, high mass transfer rates and ease to scaling-up, which becomes an attractive alternative among many traditional multiphase reactors. Numerical simulations were carried out to study the performance of monolithic reactors in present work, and dibenzothiophene was used as the sulfur model compounds in the petroleum fractions. The mass, heat transfer characteristics and the performance of hydrodesulfurization of dibenzothiophene and thiophene were investigated in monolithic reactors under Taylor flow and film flow regimes, so as to provide a basic basis for the research of monolithic reactors technology.First, two types of monolithic reactor model were established basing on the analysis of the characteristics of monolithic reactors:pseudo-homogeneous model and heterogeneous model. The Taylor flow and film flow of monolithic reactor were studied under both two models. Then, the mathematical models were listed on the basis of physical models. The concentration, temperature distributions and the yield based on reactor volume were calculated by MATLAB under Taylor flow and film flow regimes. The mass, heat transfer characteristics and the performance of monolithic reactors under two flows were also studied. The results show that:Monolithic reactors have good gas-liquid and solid-liquid mass transfer characteristics in two flow regimes; In monolithic reactors, The heat transfer resistance is very small under Taylor flow regime but a little bigger under film flow regime; it could be ignored the influence of temperature on the performance of monolithic reactors in this reaction progress(pressure is1.8×107Pa, temperature is598K, the concentration of dibenzothiophene is47.3mol/m3, liquid superficial velocity uL is0.01m/s under film flow regime and0.046m/s under Taylor flow regime), because it had a very small temperature change in reactor; The performance of monolithic reactor is poorer than trickle reactor under hydrodesulfurization of dibenzothiophene but better than trickle reactor under hydrodesulfurization of thiophene.