CFD investigation of CO2 capture by methyldiethanolamine and 2-(1-piperazinyl)-ethylamine in membranes: Part B. Effect of membrane properties

• MDEA/PZEA was for the first time used as the absorbent in the membrane gas absorption.
• A general mass-transfer model was developed for CO2 transport in a hollow fiber membrane contactor.
• Increase of the membrane length, number of fibers and porosity-to-tortuosity ratio had a positive effect on CO2 capture.
• Increase of the membrane thickness, inner fiber radius and inner module radius had a negative effect on CO2 capture.

Since the global warming is gradually increasing, the membrane gas absorption (MGA) method for CO2 separation has been intensively focused. This present study develops a 2D mass-transfer model and investigates the effect of membrane properties on the absorption performance. Chemical absorption of CO2 from flue gas in a gas–liquid hollow fiber membrane contactor (HFMC) was firstly studied using a blend of MDEA/PZEA. The modeling predications are in good agreement with the literature results. Thus, this mass-transfer model could be reliable for predication of CO2 absorption in a HFMC. Also, the simulation results indicated that increasing the membrane length, number of fibers and porosity-to-tortuosity ratio had a positive effect on CO2 capture. On the other hand, the removal performance for CO2 enhanced with a decline in the membrane thickness, inner fiber radius and inner module radius. Furthermore, this work was helpful for the selection of suitable membrane properties applied in gas separation, and provided suggestions for the experimental and industrial applications.