Numerical Investigation of Micro-Scale Liquid Flow and Mass Transfer in Kelvin Cell and Corrugated Sheet Structured Packings

Space constraints in shipboard carbon capture require compact absorbers with high gas–liquid mass-transfer efficiency. However, the performance of emerging packing geometries cannot be inferred reliably from bed-scale correlations alone because liquid distribution and interfacial transport depend on unit-cell flow organization. This study aims to compare the micro-scale hydrodynamics and CO2 mass-transfer behavior of the Kelvin cell and a Mellapak 250Y corrugated sheet unit using three-dimensional CFD simulations over liquid loads of 10 to 100 m3/(m2·h). The corrugated sheet guides liquid mainly along corrugation crimps, whereas the Kelvin cell redistributes liquid through its strut network and node intersections. For the M250Y unit, the periodic dripping cycle shortens as liquid load increases, and liquid holdup reaches only about 8% at 100 m3/(m2·h). In contrast, the Kelvin cell evolves from discrete dripping to liquid bridging and secondary breakup, maintains a liquid holdup about 3 to 6 times that of the corrugated sheet and delivers 2 to 3 percentage points higher mass-transfer efficiency. These results suggest a local hydrodynamic and mass-transfer advantage of the Kelvin cell over the M250Y benchmark under the present REU-scale conditions.