COMSOL Multiphysics® Simulation of Flow in a Radial Flow Fixed Bed Reactor (RFBR)

A. G. Dixon [1], D. S. Polcari [1], A. D. Stolo [1], M. Tomida [1],
[1] Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA

For design of radial flow fixed bed reactors, it is important to ensure proper flow distribution through the catalyst bed. A 2D axisymmetric model of a radial-flow reactor was used to evaluate flow maldistribution through the catalyst bed and the pressure drop through the reactor for a specified flow rate. Effects of different catalysts, screen sizes and flow direction were simulated. Factors which improved misdistribution, smaller catalyst particles, lower screen open fraction, and normal flow direction, also resulted in higher pressure drop through the reactor. The simulations indicated that reactor design to reduce pressure drop in the inlet and outlet channels is a major concern, while the catalyst bed specification is a trade-off between desired low pressure drop and better catalyst utilization with low maldistribution.