A novel 5-sulfosalicylic acid - Polyvinyl alcohol - Hydroxyethyl cellulose vapor permeation membrane for gas dehumidification

The crystallinity and the hydrophilicity are the two main factors influencing the membrane's vapor permeability for gas dehumidification. Herein, a novel 5-sulfosalicylic acid-polyvinyl alcohol-hydroxyethyl cellulose (SSA-PVA-HEC) vapor permeation membrane composing SSA capturing water layer and PVA-HEC transporting water layer was prepared. To reduce membrane crystallinity and increase vapor permeability, HEC was added to the PVA membrane matrix to form a transporting water PVA-HEC layer. To further improve the PVA-HEC layer's permeability, the surface of the PVA-HEC membrane was modified by the hydrophilic SSA, which acted as a capturing water layer. The results showed that the water vapor permeability of the SSA-PVA-HEC membrane improved from 1.19 × 104 to 1.52 × 105 Barrer. After dealt with SSA-PVA-HEC membrane, the relative humidity (RH%) of the feed (humid nitrogen) decreased from 90% to 23.4%. Overall, the low cost and the excellent dehumidification performance of the SSA-PVA-HEC membrane make it possible for industrialization.