(231b) Avoiding Fluidization in 3-Phase Packed Bed Reactors

Walker, J., The Dow Chemical Company
Deshpande, S., The Dow Chemical Company
Hickman, D. A., The Dow Chemical Company
In packed bed reactors, care must be taken to operate the bed well below the fluidization velocity in order to avoid motion of the particles and subsequent deterioration of the catalyst. For 2-phase reactors (gas-solid or liquid-solid), the physics are well understood. However, in co-current upflow reactors where a gas-liquid mixture is passed through a bed of packed solids, the bed becomes partially or completely fluidized at conditions well below the minimum fluidization velocity of either the gas or liquid phase alone.

In this study, a series of experiments varying the particle size, density, viscosity, and relative gas-liquid flowrates are varied to characterize the minimum fluidization conditions for the system. Computational Fluid Dynamics simulations in OpenFOAM are used to characterize the forces acting on the particles to elucidate the relevant physics.