Hydrodenitrogenation And Hydrodearomatization Kinetic Models Of Diesel Oil

At present,under the stringent laws and regulations,the raw oil of diesel oil processing in China is gradually inferior.It is necessary to develop more efficient diesel oil hydrofining catalysts to meet the requirements of the current national VI diesel oil standard.In this paper,a series of experiments(courtesy of Beijing Research Institute of Petrochemical Technology)were carried out in a high-throughput experimental unit over three kinds of catalysts(CoMo,NiMo,NiMoW).The effects of temperature,pressure,volume ratio of H2 to oil on the hydrogenation reaction of diesel oil were investigated.The kinetic models of hydrodenitrogenation and hydrodearomatization under isothermal conditions were established.The self-inhibition influence of nitrogen-containing compound was considered in the hydrodenitrogenation kinetic model.The competitive adsorption between nitrogen compounds and aromatics was considered in the hydrodearomatization kinetic model.The hydrodenitrogenation kinetic model and the hydrodearomatization kinetic model were established.The experimental data of the three catalysts were used to estimate the model parameters.The Runge-Kutta method was used to solve the model,and the Levenberg-Marquardt optimization algorithm was used to estimate the model parameters.The one-lump hydrodenitrogenation kinetic model and the two-lump hydrodenitrogenation kinetic model were established for hydrodenitrogenation reaction respectively.The mean absolute fitting errors of the one-lump hydrodenitrogenation kinetic model for CoMo,NiMo and NiMoW catalysts were 4.34 mg/kg,3.56 mg/kg and 3.21 mg/kg,respectively.The mean absolute fitting errors of the two-lump hydrodenitrogenation kinetic model for CoMo,NiMo and NiMoW catalysts were 3.93mg/kg,4.37 mg/kg and 3.06 mg/kg,respectively.The mean absolute fitting errors of different lumps in the hydrodearomatization kinetic model were 0.0055 w/w,0.0054 w/w,0.0014 w/w and 0.0083 w/w for CoMo catalysts,respectively;0.0070 w/w,0.0071 w/w,0.0016 w/w and 0.011 w/w for NiMo catalysts;0.0070 w/w,0.0076 w/w,0.0013 w/w and 0.011 w/w for NiMoW catalysts.The validation results with the experimental data of catalyst grading showed that the two kinetic models are reliable.The loading of different catalysts with different loading orders and different loading amounts is called catalyst grading.The gradation and combination of different catalysts can produce better catalytic performance than single catalyst.After the establishment of a reliable kinetic model of single catalyst,the gradation kinetic model was established.Then,the isothermal reactor and adiabatic reactor were simulated and predicted by using the kinetic models established in this paper,which can provide a theoretical basis for the optimization of diesel oil hydrofining process.