Deactivation And Kinetics Of Residue Hydroprocessing Catalysts

The HDM catalyst and the HDS catalyst independently developed by SINOPEC Da-lian(Fushun)Research Institute of Petroleum and Petrochemicals are used.The deactivation experiment and kinetic experiment of the catalysts are designed in a bench-scale fixed bed re-actor.The deactivation rule and hydrogenation performance of the two catalysts are analyzed.Based on this,the kinetic models of deactivation,hydrotreating and hydrocracking were pro-posed respectively.A down flow fixed bed residue hydrotreating process with two reactors in series is used.Under the operating conditions of the 1st reactor bed temperature of 415?,the 2nd reactor bed temperature of 425?,reaction pressure 15.0 MPa,hydrogen-oil ratio 500 v/v,and liquid hourly space velocity 0.8h-1,the experiment were carried out and a series of deactivated cata-lysts have been obtained under different operating times.The catalysts were characterized and the results showed that the reason and rule of deactivation of the two catalysts are similar.The rapid deactivation at start-of-run is mainly caused by coke,but the effect of metal sulfide dep-osition at this stage can not be ignored;as the running time goes on,the effect of metal sulfide deposition on catalyst deactivation is more than that of coke,resulting in its slow deactivation in middle-of-run.Based on the analysis of catalyst deactivation,a new deactivation model con-sidering the combined effect of coke and metal sulfide deposition was proposed and success-fully applied to the kinetics of residue hydrotreating and hydrocracking.Two sets of controlled hydroprocessing of residue in fixed bed were used.Under the oper-ating conditions(395-420? the 1st reactor,405-430? the 2nd reactor,15.0 MPa,300-700 v/v,0.6-1.0 h-1),the kinetic experiments of residue hydroprocessing were carried out.Through the analysis of the experimental results,it was found that increasing the temperature and decreasing the space velocity can significantly increase the hydrogenation efficiency of the two catalysts,but the hydrogen-oil ratio has a limited effect.Also,the hydrogenation efficiency of the HDS catalyst was higher,and its optimal active temperature was higher than that of the HDM catalyst.Based on kinetic experimental data and deactivation model,a kinetic model of hydrotreating reaction in the form of n-order power-law equation and a four lumped kinetic model of hy-drocracking reaction were established and verified.The verification results show that the aver-age relative error between the predicted value and the experimental value is less than 5%,re-gardless of the hydrotreating model or the hydrocracking model.