Pervaporation and vapor permeation characteristics of BTESE-derived organosilica membranes and their long-term stability in a high-water-content IPA/water mixture

• Organosilica membranes were applied for dehydration of IPA with PV and VP operation.
• BTESE membrane showed excellent stability under high-water-content system.
• BTESE membrane was stable in long-term PV of 50 wt% IPA aqueous solution at 75 °C.
• Permeation resistance of support layers impact the permeation performance.

Bis(triethocysilyl)ethane (BTESE)-derived organosilica membranes were applied for the dehydration of aqueous isopropanol (IPA) solutions in pervaporation and vapor permeation. The stability of the membranes under high-water-content systems was demonstrated in pervaporation and vapor permeation. The membranes showed excellent stability in the long-term pervaporation of a 50 wt% IPA aqueous solution at 75 °C. The membranes were also stable in vapor permeation with a high-water-content stream (IPA concentration of 50 wt%) at 100 °C. These results clearly demonstrated that BTESE-derived organosilica membranes are applicable for the dehydration of high-water-content mixtures. The effect of the feed component and operating temperature on dehydration performance was also investigated. An analysis of the permeation resistance through the membranes was conducted based on a simple series-resistance modeling approach and revealed that the permeation resistance of the support layer strongly inhibited the water permeability, particularly when the water content in the feed was high.