Dynamic Impacts of Catalyst Management on Self-fluidized Pump-Free Ebullated-Bed Reactor

Abstract

Ebullated-bed residual oil hydroprocessing is advantageous at reaction efficiency and operation stability, and the fluidization state of catalyst bed enables the reactor to manage bed activity by on-stream withdrawal and addition operations. In this study, the catalyst management process for pump-free ebullated-bed reactor was studied; the flow field, catalyst profile, catalyst uniformity, and bed holdup were simulated by multi-phase computational fluid dynamic simulation. The results showed that, the mass fraction of low-activity spent catalyst could reduce by a quick withdrawal operation; one single operation cycle could increase the average bed activity by 1.5%, which was able to compensate the deactivation rate of catalyst. This study developed a theoretical tool for studying the dynamics of ebullated-bed reactor, and provided operational guidance on the design and optimization of pump-free ebullated-bed residual oil hydroprocessing process.