Dynamic Modeling and Simulation of Acid Gas Removal Using Hollow Fiber Membrane Contactors: A Novel Design Approach

The growing concentration of carbon dioxide (CO₂) emissions from industrial processes has become a major environmental concern. Hollow Fiber Membrane Contactors (HFMCs) have emerged as a promising alternative for efficient CO₂ capture, offering higher mass transfer rates, lower energy requirements, and reduced solvent losses. However, optimizing the design and operational parameters of HFMCs remains a challenge, requiring a detailed investigation of membrane characteristics, fluid dynamics, and process variables. This study develops a numerical model to simulate CO₂ absorption in HFMCs under various conditions. The model is based on mass transfer equations, membrane diffusion mechanisms, and reaction kinetics of CO₂ absorption into aqueous monoethanolamine (MEA). The results were validated by comparing the simulated CO₂ capture performance with experimental data from previous studies. Key Numerical Findings are: Higher liquid flow rates (0.8 m/s) enhanced CO₂ absorption efficiency, reaching 95.6% removal under optimal conditions. However, increasing the solvent flow beyond this threshold showed negligible improvement due to mass transfer limitations, increasing gas velocity negatively affected CO₂ capture, reducing efficiency from 93.1–85.7%, as a result of reduced residence time, membrane porosity played a crucial role in mass transfer performance, with an optimal porosity of 75% providing the highest absorption rates while maintaining structural stability, the numerical model showed a high level of accuracy, with a deviation of less than 1% compared to experimental and industrial data, and a modified HFMC design with shell-side barriers significantly improved CO₂ absorption compared to traditional HFMC configurations. The study confirms that HFMCs can outperform conventional CO₂ capture technologies if proper operational parameters and membrane characteristics are optimized.