Features of Fluidized Catalyst Beds for Proper Design and Operation of Catalytic Reactions

Fluidized catalyst beds have been used in chemical and refinery processes and studied extensively for more than 50 years. However, the features of this reactor are still not understood perfectly. There is still much more to learn about the fluidized catalyst beds. It is important to elucidate the bubble behavior and the contact between catalyst particles and reactant components in the reactors. Understanding the features of the reactors contributes to the proper catalyst design together with the appropriate design and operation of the reactors. In this paper, the influence of gas properties on the bubble behavior is described, and pseudo-3-dimensional images of bubbles are shown. The important effects of direct and successive contact in the bed are discussed regarding conversion and selectivity. The reaction analysis showed that the selectivity could be improved by the effective use of the direct contact catalyst particles. The synergy effect of the three factors, i.e., catalyst activity, contacting feature between gas and particles, and transport/mixing properties in the bed, plays a salient effect in raising selectivity of consecutive reactions.