(453b) Flow Regime Transition in Trickle Bed Reactors

Authors: 
Honda, G. S., Purdue University
Varma, A., Purdue University
Hickman, D. A., The Dow Chemical Company

The hydrodynamics of a trickle bed impact reactor performance through changes in mass transfer with flow regime [1, 2]. Depending on the reaction chemistry (liquid limiting or gas limiting), operation in one flow regime or another may have a positive or negative influence on reaction rate and yield of the desired product. Accurate characterization of the boundary between low interaction and high interaction regimes is therefore imperative. While a significant number of studies have been reported in the literature, none are available which experimentally discern the independent impacts of void fraction and particle size/shape on the transition. In this work, the flow regime transition is measured by visual observation and analysis of the standard deviation of the pressure drop for a range of packing media. A number of different particle shapes and sizes are investigated and the void fraction is varied by inclusion of fines. In this way, the effects of particle shape, size, and bed void fraction on flow regime are determined.

[1] Wilhite, B.A.; Wu, R.; Huang, X.; McCready, M.J.; Varma, A. AIChE J. 2001, 47 (11) 2548.

[2] Al-Dahhan, M.H; Larachi, F.; Dudukovic, M.P.; Laurent, A. Ind. Eng. Chem. Res. 1997, 36 (8) 3292.