Enhancing CO2 capture performance by changing membrane fiber arrangement in multi-fiber membrane contactors

Membrane absorption has garnered significant attention due to its ability to combine the advantages of membrane separation and chemical absorption methods. During the scale-up of membrane absorption equipment, the fluid flow and mass transfer processes tend to have serious non-ideal effects, arising from the increase in aspect ratio and the number of membrane fibers. However, traditional one-dimensional (1D) and two-dimensional (2D) models are unable to describe the impact of geometry on mass transfer performance. In this study, a three-dimensional (3D) steady-state model is established to simulate the mass transfer process in a multi-fiber membrane contactor using COMSOL Multiphysics software. The 3D steady-state model is proven to be able to accurately predict the CO 2 absorption flux (J CO2 ) under various operating conditions by comparing the simulation results with experimental data. The results indicate a strong correlation between mass transfer performance and fluid velocity distribution. To further explore the flow behavior of gas and liquid at different locations, a 3D dynamic simulation model is developed and compared with experimental data. This model can describe the non-ideal flow behavior and the characteristics of gas and liquid phases in reactors with complex geometries. The results of the 3D dynamic model show that there are priority and slow regions for fluid flow, and CO 2 mass transfer performance can be enhanced by concentrating the membrane fiber arrangement in the priority region. The model developed in this study can be used to evaluate defects in fluid flow patterns, such as channeling, back mixing, and tailing. Furthermore, the 3D steady-state and dynamic models can guide the design of membrane contactors, optimize operating conditions, and provide a reference for analyzing fluid flow morphology and structural optimization in membrane contactors.