Gas tight alpha-alumina supported hydroxy sodalite membranes were employed in pervaporation, testing the acid and base stability of the membranes through prolonged dehydration of acetic acid/water mixtures and sodium hydroxide solutions with different concentrations at 473 K and 2.2 MPa cross-membrane pressure. Under continuous operation for approximately 320 h, hydroxy sodalite membranes showed good acid and base stability within a feed pH range of 2.9-13.7. Under these conditions the membrane showed absolute selectivity towards water, and the flux through the membrane remained fairly stable. The membranes were also employed in dehydration of acetone/water mixtures at different temperatures and feed compositions. The membrane exhibited a water/acetone separation factor larger than 10(6). (C) 2010 Published by Elsevier B.V.