Analysis of CO2 Separation with Aqueous Potassium Carbonate Solution in a Hollow Fiber Membrane Contactor

Hot potassium carbonate solution is a promising absorbent for economical sequestration of CO 2 from flue gas. In the present study, a 2D mathematical model was developed to analyze the absorption of carbon dioxide from a gas mixture into an aqueous solution of potassium carbonate using a microporous hollow fiber membrane contactor operated under nonwetted or partially wetted conditions. The set of partial differential equations for the liquid, membrane and gas phases were solved by applying a numerical procedure, and the model results were validated with available experimental data in the literature. A parametric study was done using the validated model in order to achieve an optimized CO 2 capture. It was found that the rate of absorption increases significantly with increasing the liquid temperature, and there is an optimum carbonate concentration which gives maximum absorption flux at each solution temperature. A comparison between potassium carbonate and diethanolamine solutions was done under nonwetted and partially wetted conditions. The results revealed that potassium carbonate can give higher CO 2 recovery at optimum conditions. Considering the other advantages of K 2 CO 3 solution over alkanolamines such as lower cost and easier regeneration, it can be a suitable choice for CO 2 absorption by hollow fiber membrane contactors.