Suitable membrane absorption mode for diluted gas absorption - hydrophobic or hydrophilic

Abstract

The hydrophobic membrane dominates in the membrane-based gas absorption processes, but sometimes the hydrophilic membrane can show advantages in diluted gas absorption. In order to further study the effect of wettability on absorption performance and select suitable membrane absorption modes, a mass transfer model based on the interfacial partition coefficient (K) was proposed. K simply described the gas–liquid interface relationship and could make a link among various absorption systems for easy comparison. Based on the K, two extreme wetting modes of hydrophobic and hydrophilic ceramic membranes were used to investigate and compare the absorption performances between them, and combining K with the actual interfacial equilibrium relationship to select a suitable absorption mode. The results showed that the hydrophilic membrane is indeed suitable for the absorption of diluted gases, and the K introduced into the model helped to quickly determine the appropriate membrane contactor according to the absorption requirements.