INHIBITION EFFECTS OF QUINOLINE ON THE HYDRODESULFURIZATION OF DIBENZOTHIOPHENE AND ITS REACTION KINETICS OVER NiW/Al_2O_3 CATALYST

The inhibition of nitrogen compound quinoline for the hydrodesulfurization(HDS) reaction of dibenzothiophene(DBT),the model compound of S-bearing aromatics in diesel,was studied in a pressured trickle bed reactor over a commercial NiW/Al_2O_3 catalyst(RN-10).The effects of the reaction conditions and the concentration of quinoline in the feed on the HDS of DBT were investigated,at the quinoline mass fraction of 0.5%-1.5%,total pressure of 4.0-5.6 MPa and temperature of 290-380℃.It was found that quinoline strongly inhibited the HDS of DBT,and with the increase of concentration of quinoline,the inhibition effect increased significantly.In the HDS of DBT,the inhibition of quinoline for hydrogenation(HYD) route was more severe than for direct desulfurization(DDS) route.High temperature was favorable to both HYD and DDS,but could cause the decrease of biphenyl(BP) selectivity via DDS route.High pressure could improve the selectivity of HYD products.The inhibition effect of quinoline for HDS of DBT was quantitatively described in a proposed modified pseudo first-order kinetic model,into which an adsorption equilibrium constant of quinoline was introduced,and the apparent reaction rate constants of DBT HDS were obtained at different mass fractions of quinoline.The kinetic model was well fitted with the experimental data.