Development And Application Of Molecular-level Kinetic Model For Catalytic Conversion Of Heavy Oil

The reaction kinetic model plays a crucial role in the development and optimization of petroleum processing technology.Molecular-level kinetic modeling has the advantage of predicting detailed composition and bulk properties of products,and will provide a more effective technical route for smart management of refineries.In this work,based on the concept of molecular management,a method for developing a molecular-level kinetic model was proposed and applied to develop the kinetic model of slurry oil hydrotreating and heavy oil fluid catalytic cracking(FCC).A molecular-level kinetic model for heavy oil catalytic conversion at the pathway level was developed based on a hybrid structural unit and bond-electron matrix framework.A method for collecting and establishing reaction rules in terms of the reaction family were proposed,and the automatic generation and visualization of a rulebased reaction network was developed.On this basis,the auto-conversion between reaction network and reaction rate expression was developed,and the reaction rate equations based on Arrhenius equation or LHHW formulation were automatically developed,which could be applied to the homogeneous or heterogeneous reaction process.To reduce the complexity of model solving,the linear free energy relationship and quantitative structure-reactivity correlations was used to reduce the number of model parameters to a manageable scale.To verify the feasibility of the method,a molecularlevel kinetic model for the Venezuelan vacuum residue pyrolysis was developed.The tuned model showed good agreement with the experimental measurements for different reaction conditions.After establishing the modeling method,a molecular-level kinetic model of slurry oil hydrotreating and heavy oil FCC was developed,respectively.According to the reaction mechanism,24 reaction rules for hydrotreating and 23 reaction rules for FCC were collected and established.In addition,a method combining the reactor mathematical model and the molecular-level kinetic model was also proposed.For slurry oil hydrotreating,the molecular-level kinetic model coupled with a trickle-bed reactor mathematical model with vapor-liquid equilibrium was developed.The model was able to predict the concentration distribution of each species along the reactor and obtained the molecular-level transformation of key components in the hydrotreating.For heavy oil FCC,the mathematical model of FCC reactor was delivered to the molecular-level kinetic model,and the model parameters were tuned using experimental data obtained from pilot FCC unit.The tuned model was able to predict the yield of each fraction and main bulk properties of gasoline.Overall,the successful development of the above models proves that the molecular-level kinetic model can achieve accurate simulation of heterogeneous catalytic system for petroleum processing and provide theoretical guidance for the development of molecular-level reaction process models.