DYNAMICS OF FCC DOWNER REACTOR

Abstract

FCC process plays an important role in heavy oil cracking; nowadays this process is becoming increasingly important as a potentially flexible means to respond to change in petrochemical product demand. Great interest in this direction has been encouraged by the relatively novel FCC process configuration, in which a down-flow cracking reactor or Downer reactor replace conventional riser reactor. Downer reactor has unique features where gas and solids move downward co-currently and it accommodates high-severity operation at the initial stage. The operation- prinples of downer reactor are close to plug flow reactor. It has been reported that the downer reactor have major advantages over the conventional riser. Downer reactor usually reduces the contact time during thermal cracking and eliminates back mixing which produce dry- gas. Mathematical model for downer reactor has been developed. To model the cracking reaction of gas oil to lighter fractions and coke five-lump model was used. Nine kinetic parameters and one catalyst deactivation activity were considered. To generate the steady-state and unsteady state model the hydrodynamics parameter gross assumption were made. Ordinary differential was used to solve steady-state and partial differential equation was used to solve the unsteady state, by using MTLAB. In this study, flow rate , temperature profile and concentration profile were plotted.