Catalytic reforming is a process of great interest to petroleum refinery and petrochemical industry for the production of aromatic compounds that are raw materials for petrochemical products and gasoline additives. The modern reforming units are characterized by in situ regeneration of catalyst and by continuous addition of catalyst to operating reactor. One of the key aspects of this CCR is catalyst circulation between reactor and regenerator. This circulation is controlled be lift engager situated at the bottom of both reactor and regenerator. Hydrodynamics of gas and solid phases plays important role in governing the performance of lift engager. In this work, Eulerian – Eulerian two fluid model (TFM) was used to study the hydrodynamics of the lift engager.
Preliminary numerical experiments were carried out to show effect of drag model on dense and dilute phase flow regimes. The parametric study of primary and secondary gas was reported on time average profiles of slip velocity, catalyst velocity and volume fraction along the height of lift line. This study shows that high primary to secondary gas ratio results in high slip velocity in the lift line. The catalyst flow rate at the outlet was found to fluctuate with time. Time series analysis of fluctuations in catalyst flow rate signal was carried out. Low frequency oscillations were successfully mapped to the frequencies of the solid bed in the lift engager. The multiphase flow model and analyses presented in this work reveals useful information for designing and troubleshooting lift engagers.