Modeling Optimization Of Fluid Catalytic Cracking Reactor-regenerator System Based On Special Pseudo-components

Fluid catalytic cracking reactor-regenerator(FCCR-RG) system is a critical process of petroleum refineries which mainly consists of stock oil cracking, products separation and catalysts regeneration with the corresponding equipments to be risers(reactors), strippers/disengagers and regenerators. In modeling a FCCR-RG system, the mainly challenging problems are the Fluid catalytic cracking(FCC) process containing large number of cracking reaction along with the catalyst deactivation, the complex hydrodynamics, the strong coupling effects between coke combustion reactions with complex thermal effects, as well as the uncertainty coupling problems existing in the connection of risers and regenerators. Therefore, FCCR-RG modeling process inevitably involves the characterization of stock and product oils, the construction of oil cracking and coke combustion systems, the establishments of coking and catalyst deactivation mechanism, the nonlinear relationships in reaction process, as well as the expression of model steady and dynamic characteristics.The FCC kinetic models proposed in the past can be primarily classified as lump, single-event kinetic, pseudo-components(PCs) and special pseudo-components(SPCs) models by the entities used to express the oil. The models based on the first three theories need to adjust the parameters or even to be rebuilt. The existing SPCs models have solved the previous challenge well by setting light and heavy components, but also have several prominent problems: (1) The number of possible reactions is to tens of thousands forming a serious burden of computation;(2) Over 1/3 of the possible reactions are exothermic, which is physically unreasonable. A new generic reaction in the form of PCi?PCm + [i,m]?PCm + ?i,m coke + surplusage as well as the new cracking kinetics and coking mechanism is proposed based on the transition state theory.Experiments prove that the new FCCR model is much more powerful in correlating and predicting the production performance. Besides, the maximum information entropy method(MIEM) based on Gaussian distribution is tried in this paper to improve the characterization of FCC product oils and surely obtaining some success.