CO₂ removal by single and mixed amines in a hollow‐fiber membrane module—investigation of contactor performance

This work investigates CO 2 removal by single and blended amines in a hollow‐fiber membrane contactor (HFMC) under gas‐filled and partially liquid‐filled membrane pores conditions via a two‐scale, nonisothermal, steady‐state model accounting for CO 2 diffusion in gas‐filled pores, CO 2 and amines diffusion/reaction within liquid‐filled pores and CO 2 and amines diffusion/reaction in liquid boundary layer. Model predictions were compared with CO 2 absorption data under various experimental conditions. The model was used to analyze the effects of liquid and gas velocity, CO 2 partial pressure, single (primary, secondary, tertiary, and sterically hindered alkanolamines) and mixed amines solution type, membrane wetting, and cocurrent/countercurrent flow orientation on the HFMC performance. An insignificant difference between the absorption in cocurrent and countercurrent flow was observed in this study. The membrane wetting decreases significantly the performance of hollow‐fiber membrane module . The nonisothermal simulations reveal that the hollow‐fiber membrane module operation can be considered as nearly isothermal.