Experimental study and modeling of direct contact and vacuum membrane distillation of carbonate solutions

Reduction of CO2 emissions is a big challenge in the context of climate change. For this reason, new processes are being studied for the reduction of CO2 emissions but also for the CO2 revalorization. The aim of this study is to increase the understanding of the mass transfer in membrane distillation for purpose of CO2 revalorization. More specifically, the direct contact and vacuum membrane distillation configurations are studied. Therefore, experiments with different operational conditions i.e. the temperature, the flow rate, the concentration and the pressure have been performed in order to compare the overall mass transfer coefficient between both configurations. It has been observed that the mass transfer coefficients have similar values for both direct contact and vacuum configurations. However, the mass transfer coefficients obtained with the vacuum configuration show a more stable behavior. A CFD modeling has also been engaged to obtain the temperature profiles inside the membrane module for the direct contact configuration. This modeling allowed to see that these profiles are not linear inside the membrane module.