CO2 capture and recovery by the use of membrane crystallization

Nowadays CO2 emissions are a global problem that requires immediate solutions. Membrane systems seems to be a promising solution due to their low energy consumption, their high mass exchange surface and their better scale-up possibilities. Moreover, conversion of CO2 into Na2CO3 could lead to an interesting economic repurposing of the greenhouse gas. That is why Na2CO3 recovery by using membrane distillation-crystallization was studied. In a very simple lab-scale system connecting a feed Na2CO3 solution and an osmotic NaCl solution to one or two membrane modules, it was possible to produce Na2CO3.10H2O crystals during more than one hour. Water removal is affected by both concentration and temperature, which can be adapted to control crystallization. Studies in larger scale systems have to be carried out to reinforce the promising results obtained in lab-scale system.