INFLUENCE OF MASS-TRANSFER COEFFICIENT FLUCTUATION FREQUENCY ON PERFORMANCE OF 3-PHASE PACKED-BED REACTORS

In three-phase packed-bed reactors, different flow regimes exist due to intrinsic hydrodynamic instability. Among these. the pulsing-flow regime is characterized by fast alternating of ''liquid-rich plug'' (pulse) and ''gas-rich plug'' (base) along the column, which results in a periodically changing environment for the stationary catalyst. In this paper, the influence of pulsing frequency on several different reaction systems is explored based on models that describe a small local region within a multiphase packed-bed reactor. It is found that the time-averaged reactor performance indexes including conversion of key reactant, selectivity of desired product over waste and yield of desired product can be increased significantly over other flow regimes such as the trickling-flow regime. The extent of enhancement varies substantially with pulsing frequency, and it appears that by carefully tuning it, a great potential exists for enhancing reactor performance.