Research On The Lumped Reactions Kinetic Model For FDFCC Process

Comprehensive reviews of the development of the clean gasoline production, the latest maximizing propene technologies for the FCC (Fluid Catalytic Cracking) process and the lumped kinetic models were done in this paper. Based on the study of the features and reaction mechanism of Flexible Dual-riser Fluid Catalytic Cracking-III(FDFCC-III) process, the reaction networks and two lumped kinetic models, a 10-lumped kinetic model for heavy oil riser and a 7-lumped kinetic model for gasoline riser, were established. The cracking reaction of resin and asphaltum into gasoline and gas were described as second order reaction and the others were first-order irreversible reactions. According to the data from pilot plant,83 kinetic parameters of the 10-lumped kinetic model for heavy oil riser and 35 kinetic parameters of the 10-lumped kinetic model for gasoline riser were calculated with the help of VC++program, and the results were optimized by BFGS method.The results showed that the features and reaction mechanism for FDFCC-Ⅲprocess could be reflected well form the parameters, especially after the consideration of second-order reaction for resin and asphaltum into gasoline and gas, relative errors of 7-lumped kinetic model were less than 1% and 10-lumped kinetic model were less than 5%,which were better than the model in which all reactions were one-order irreversible ones. Further more,41 unit factors for heavy oil riser and 18 unit factors for gasoline riser were set with the consideration of industrial scale-up factors, then industrial verification of the models were carried out. The results showed that the relative errors between calculated values and the industrial data were less than 5%,the objective function was better and the established models were reliable. Finally, a series of operational performance charts which showed the trend of gasoline and propylene production via the changes of reaction temperature, catalyst to oil ratio and the recycle ratio were drawn for a commercial FDFCC-Ⅲunit. The charts gave reliable rules which accord to the mechanism of FDFCC-Ⅲprocess and could be used to guide industrial practices.