Effect of Particle Aspect Ratio and Shape on the Particle-Scale Dynamics of Gas–Liquid Flow through Packed Beds

Abstract

Packed beds are widely used to perform solid-catalyzed gas–liquid reactions and gas cleanup processes. In the present work, we simulated gas–liquid flow through realistic 3D particle-resolved domains consisting of cylindrical particles of varying aspect ratio (h = 1–5) and different particle shapes (Raschig ring, trilobe, daisy, and sphere) using the volume-of-fluid method. With an increase in h, we found that the number fraction of laterally oriented particles decreases and length of elongated void-throats increases. Further, we found that liquid preferentially flows over surface of laterally oriented particles and through elongated void-throats. The combined effect of h, orientation distribution, and elongated void-throats results in improved hydrodynamic performance (liquid holdup, wetting efficiency, interfacial area, and liquid distribution) with an increase in h. We also found that the hydrodynamic performance of trilobe- and daisy-shaped particles is better than cylindrical particles in terms of interfacial area due to preferential flow of liquid through the grooves on externally shaped particles.