An experiment and model of ceramic (alumina) hollow fiber membrane contactors for chemical absorption of CO2 in aqueous monoethanolamine (MEA) solutions

Abstract

The chemical absorption of CO2 in a monoethanolamine (MEA) solution by a ceramic hollow fiber membrane contactor (HFMC) was investigated experimentally and numerically to obtain the best compromise between the mass transfer coefficient and structural characteristics such as membrane pore size and porosity. The mathematical model derived is based on the three resistances in the resistance-in-series model. The accuracy of the numerical simulation was verified quantitatively by the experimental data obtained in this study. A good agreement between experimental and computational results was found with an average absolute deviation (AAD) between observed data and predicted values of 2.86%. In addition, the effects of the operating condition (i.e., gas and liquid flow rates) on the mass transfer coefficients for ceramic HFMC systems were also studied, revealing that the membrane and gas-phase mass transfer resistances were dominant factors in the overall mass transfer. In conclusion, the present study suggests that the membrane structure plays a very important role in the optimization of HFMC performance. In fact, the best results were obtained with an intermediate range of the pore size between 102 and 104 nm, corresponding to the best compromise between performance (i.e., overall mass transfer coefficient) and applicability (i.e., breakthrough pressure).