(586a) Open-Cell Foam Supports for Structured Catalytic Reactors

Structuring concepts for catalytic reactors such as the use of monolithic honeycombs and open-cell foams are promising for achieving process intensification in the chemical industries. In particular, these structured catalyst supports have the potential to eliminate the classical drawbacks of conventional randomly packed fixed-bed reactors, i.e. high pressure drop and hotspots.

The most prominent and successful examples of structured reactors are honeycomb-shaped monolithic catalysts. Owing to their excellent properties such as, e.g., exceptionally low ratio of pressure drop to geometric specific surface area, they have become the standard catalyst shape in many environmental applications. However, monolithic honeycombs lack some important properties such as, e.g., tortuosity of the flow and radial mixing since they consist of a large number of parallel straight channels with no interconnectivity.

In contrast to this, open cellular materials combine the advantages of packed beds (i.e., radial mixing and tortuosity of the flow) and honeycombs (i.e., high geometric specific surface area and low pressure drop) owing to their high porosities and their characteristic 3D cellular architecture.

In our recent research, we have investigated open cellular materials with both periodic and random cell geometries regarding their use as catalyst support. These structures were characterized with respect to their morphological/geometrical properties, fluid dynamic behavior and mass and heat transport properties. Models for the estimation of properties important for reactor design such as, e.g., specific surface area and pressure drop of such cellular materials were developed and validated.

Detailed numerical studies of such geometries and the 3D flow field along with mass and heat transport processes were carried out in order to analyze the influence of the local foam geometry on the macro transport characteristics. This allows for a more fundamental understanding of the relationship between the support structure, the local flow field, the local and global transport characteristics, and finally the reactor performance.

In our contribution, we present a comprehensive overview on our recent research on cellular materials.