Modeling and simulation of CO₂ removal in a polyvinylidene fluoride hollow fiber membrane contactor with computational fluid dynamics

This study was an attempt to develop a comprehensive two-dimensional model for removal of carbon dioxide in a polyvinylidene fluoride (PVDF) hollow fiber membrane contactor (HFMC) utilizing the computational fluid dynamics (CFD) technique. Governing equations were solved in three sections using a finite element method. Distilled water was used as a liquid absorbent in a non-wetting mode. Effectively, a comparison was made between the simulation predictions of the model and the experimental data in order to validate the developed model, which resulted into significant corroboration between them. The simulation results showed that removal percentage of CO₂ was encouraged by increasing liquid velocity. However, it was decreased by increasing gas velocity and liquid absorbent temperature. Moreover, the simulation results revealed that increasing fiber length and membrane porosity had a positive effect on the removal efficiency. It was also indicated that counter-current flow arrangement was superior to co-current at the same operating conditions by investigating the results for both flow arrangements. In this model, two different equations were used for estimating the diffusion coefficient of CO₂ in water, which the results for the removal efficiency were different.