Vapor permeation (VP) of water (H2O)/ acetic acid (AcOH) mixtures via bis(triethoxysily)ethane (BTESE) membranes

Bis(triethoxysilyl)ethane (BTESE)-derived organosilica membranes prepared using sol-gel processing, were used in vapor permeation (VP) to dehydrate aqueous acetic acid (AcOH) solutions. It was discovered that BTESE-derived membranes had outstanding stability and great permselectivity. BTESE-derived organosilica membranes showed a H 2 O/AcOH separation factor of 3000–5800 and a H 2 O/AcOH permeance ratio of 3000–5800 with the permeate flux of 12–28 ​kg ​m −2 ​h −1 for H 2 O/AcOH mixtures (AcOH: 50 ​wt%) under 120 ​°C and 100 kPaA. The superior durability of organosilica membranes was confirmed by long-term stability tests conducted in aqueous AcOH mixtures, which indicates that BTESE membranes maintained almost the stable flux and separation factors. A comparison with gas permeation properties indicates that the molecular sieving effect dominates the separation mechanism.