Optimization of structured packings using twisted tape inserts

CFD Modeling on Hydrodynamic Characteristics of Multiphase Counter-Current Flow in a Structured Packed Bed for Post-Combustion CO2 Capture

Solvent-based post combustion CO2 capture is a promising technology for industrial application. Gas-liquid interfaces and interactions in the packed bed are considered one of the key factors affecting the overall CO2 absorption rate. Understanding the hydrodynamic characterizations within packed beds is essential to identify the appropriate enhanced mass transfer technique. However, multiphase counter-current flows in the structured packing typically used in these processes are complicated to visualize and optimize experimentally. In this paper, we aim to develop a comprehensive 3D multiphase, counter-current flow model to study the liquid/gas behavior on the surface of structured packing. The output from computational fluid dynamics (CFD) clearly visualized the hydrodynamic characterizations, such as the liquid distributions, wettability, and film thicknesses, in the confined packed bed. When the liquid We (Weber number) was greater than 2.21, the channel flow became insignificant and flow streams became more disorganized with more droplets at larger sizes. The portion of dead zones is decreased at higher liquid We, but it cannot be completely eliminated. Average film thickness was about 0.6–0.7 mm, however, its height varied significantly.