Analysis of the effect of module design on gas absorption in cross flow hollow membrane contactors via computational fluid dynamics (CFD) analysis

• CFD modeling of gas absorption in cross flow membrane hollow membrane module.
• Validation of the proposed CFD model through experimental results.
• The impact of module design on the absorption performance is investigated.
• Optimization strategy is explored to enhance performance of cross flow modules.

The performance of cross flow hollow fiber membrane contactors (HFMCs) used for gas absorption is greatly influenced by module characteristics. In this study, a comprehensive investigation has been conducted on the module design and its impact on the performance of cross flow HFMCs using computational fluid dynamics (CFD) analysis. For modules operated with liquid solvent flowing through the shell-side, the overall mass transfer coefficient is a strong function of shell-side flow behavior which in turn is determined by shell geometries. Shell-side liquid flow behavior is difficult to predict and therefore often overlooked. In this work, a CFD simulation of a lab scale cross hollow fiber membrane contactor was developed to estimate shell-side flow and overall mass transfer performance. The CFD model was validated with experimental data from the lab scale module for CO2 absorption. The validated model was then used to investigate the geometric effect of module design on the shell-side flow and consequent absorption performance. A few design factors were examined such as the shell configurations, inlet geometries, fiber bed height and packing density. This work shows that a properly designed CFD simulation can be used as a useful tool to optimize module design for cross flow membrane contactors and improve absorption performance.