Ethanol:water blends separation using ultrafiltration membranes of poly(acrylamide‐co‐acrylic acid) partial sodium salt and polyacrylamide

In this work, poly(acrylamide‐co‐acrylic acid) partial sodium salt (P(AAM‐co‐AA)Na), and polyacrylamide (PAAM) membranes were synthesized for separation of ethanol:water blends. The membrane characteristics were evaluated to determine their ability to separate mixtures of ethanol:water and get dehydrate ethanol (95 %). Synthesized membranes showed higher selectivity to ethanol compared to existing polymeric membranes. The ethanol:water blends had an ethanol concentration of 0.10 to 0.70 L/L. The results showed that a mixture of ethanol:water (75:25 L/L) can be concentrated up to 95 % ethanol. The membranes’ stability were studied in absolute ethanol and ethanol:water blend (30:70 L/L) for a period of 30 days of permanent exposure. The membrane deterioration is due to the chemical modification of the membrane active surface layer. It was found that the membranes have a high selectivity (350 times higher) compared to existing membranes, and the substantial and flow of water was 12.15 kg · m −2  · h −1 .