Effect of flow direction on the performance of radial flow catalytic reactors

The effect of flow direction in radial flow catalytic reactors was studied using a reactor model construct. Inward and outward flows result in different performance depending on the reaction type and the underlying kinetics. For irreversible reaction with power law kinetics, inward flow results in higher conversion relative to outward flow for identical set of operating conditions. The trend reverses for reversible reactions, for both exothermic and endothermic types. For Langmuir-Hinshelwood monotonic type reactions, however, inward flow is shown to be superior for both reversible and irreversible reactions. A typical industrial example for the endothermic catalytic dehydrogenation of ethylbenzene to styrene is used to directionally verify the predictions from our generic model. The results from our model predictions show that outward flow is favorable, in line with industrial practice. This study does reveal, however, that this relatively straightforward technique can be applied to gauge the superior flow direction depending on the type of reaction considered.