Hybrid ceramic-supported thin PVA pervaporation membranes: Long-term performance and thermal stability in the dehydration of alcohols

✍ Scribed by Thijs A. Peters; Nieck E. Benes; Jos T.F. Keurentjes

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 406 KB
• Volume: 311
• Category: Article
• ISSN: 0376-7388
• DOI: 10.1016/j.memsci.2007.12.005

✦ Synopsis

The long-term performance and thermal stability of ceramic-supported cross-linked poly(vinyl)alcohol membranes has been examined over a period of six months up to a temperature of 100 • C. The membrane performance gradually changes at a temperature of 80 • C. After six months the water flux has increased from 1 to 1.4 kg m 2 h -1 , while the selectivity has decreased from 450 to 300. SEM analysis gives no indication that the decrease in performance is caused by defects in the membrane layers or a decreased adherence of the PVA layer to the ␥-Al 2 O 3 support. It is more likely that observed higher water flux and lower selectivity are caused by a decrease in cross-linking of the PVA-chains due to removal of maleic acid. At a temperature of 100 • C the decline in performance is accelerated. At this temperature the selectivity drops from 300 to 25, over a period of two weeks. At 100 • C, the thermal stability of the membranes is inadequate for most practical applications.