CO2 capture using superhydrophobic ceramic membrane: Preparation and performance analysis

The application of membrane absorption for CO 2 capture has been limited by membrane wetting. In this paper, tubular Al 2 O 3 ceramic membranes (marked as M1 and M2) are hydrophobically modified by sol-gel and dip-coating method and then used for CO 2 capture. The surface morphology , surface composition, wettability and flux are characterized in detail. The mass transfer performance of M1 and M2 is studied at different gas and liquid Reynolds numbers . After modification, the surface contact angle can reach as high as 170.7°. The carbon capture performance of the modified M1 and M2 is significantly improved. Under laminar flow condition , CO 2 mass transfer coefficient increased from the initial 1.03 × 10 −4  m/s to 14.59 × 10 −4  m/s, and the CO 2 capture efficiency increased from the initial 28.55%–98.55%. The mass transfer resistance of ceramic membrane contactor is also analyzed. The resistance of liquid phase plays a leading role in the mass transfer performance in laminar flow state . For non-wetting membrane, membrane thickness has little effect on the mass transfer performance. In addition, it is shown that the superhydrophobic M1 and M2 exhibit excellent corrosion resistance . The research in this paper shows that superhydrophobic ceramic membrane is more suitable for CO 2 capture in industrial production.