S. Trunk, H. Freund
Chem. Eng. Process. 195 (2024) 109617

In the field of heterogeneous catalysis, additively manufactured so-called Periodic Open Cellular Structures (POCS) applied as catalyst supports have demonstrated their advantages over conventional randomly packed bed reactors in terms of heat management and pressure drop (Busse et al., 2018; Inayat et al., 2016). Since the internal flow field and the pressure drop are mainly influenced by the geometrical properties of the unit cell (unit cell type, strut diameter and cell size), the resulting transport characteristics of the structure are already determined during the design phase of the unit cell (Horneber, 2015). By inserting one POCS based on a diamond unit cell (offset structure) into the cavities of a second diamond cell structure (fix structure), a completely new type of so-called interpenetrating Periodic Open Cellular Structures (interPOCS) is formed which allows for an in operando adjustment of the global and local morphological properties of the structure (Do et al., 2017; Do et al., 2020). With detailed, spatially resolved computational fluid dynamics (CFD) simulations using the open source toolbox OpenFOAM® (Weller et al., 1998) and an additional in-house random-walk particle tracking implementation called disTrackFoam (Trunk et al., 2021), we systematically investigated the local and global flow characteristics within the interPOCS in dependency of the relative positioning of the fixed and offset structure. The obtained results show that this highly adjustable structure allows for a broad variation of flow characteristics in a chemical reactor without changing the system’s periphery. This study demonstrates that interPOCS represent a completely new application of additively manufactured catalyst support structures enabling highly flexible in operando tuning of the flow field and mass transport in a heterogeneously catalyzed reactor system.

https://authors.elsevier.com/a/1iACCw2gr0DwT