CO2 stripping from diethanolamine using membrane contactors: Model validation and membrane wettability

Abstract

CO2 has been considered as the main greenhouse gas that contributes to global warming. Recently, membrane gas-liquid contactors are considered as alternative technique for gas absorption/desorption instead of conventional column. One of the undesirable features for this technique is the membrane wettability. In the present work, CO2 desorption (stripping) from diethanolamine (DEA) solution using polyvinylidene fluoride hollow fiber membrane contactor is theoretically investigated. A comprehensive two dimensional mathematical model is developed to evaluate the membrane wettability when DEA solution is used at different operating conditions such as sweeping gas flow rate, initial CO2 loading, liquid phase temperature and flow rate of liquid phase. The model results revealed that the effect of sweeping gas flow rate on the stripping flux was negligible. In contrast, CO2 stripping flux was proportionally increased when the temperature and liquid phase flow rate were increased. In addition, the simulated results were compared with the experimental data obtained from literature which were in good agreement. Moreover, the results revealed that the PVDF membrane was suffered from wetting at studied operating conditions.