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 t o intrinsic hydrodynamic instability. Among these. the pulsing-flow re gime is characterized by fast alternating of ''liquid-rich plug'' (pul se) 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 reacti on systems is explored based on models that describe a small local reg ion within a multiphase packed-bed reactor. It is found that the time- averaged reactor performance indexes including conversion of key react ant, selectivity of desired product over waste and yield of desired pr oduct can be increased significantly over other flow regimes such as t he trickling-flow regime. The extent of enhancement varies substantial ly with pulsing frequency, and it appears that by carefully tuning it, a great potential exists for enhancing reactor performance.