Abstract
Reverse osmotic concentration of aqueous ethyl alcohol solution was carried out using cellulose acetate membrane (CA) and composite membranes (PEC). Separation of ethyl alcohol and flux through the membranes were measured under the following conditions : concentration of ethyl alcohol 2, 5, 10-15, 20-25 and 50 wt%, operating pressures 2, 4, 6 and 8 MPa. The most favorable separation obtained with CA membrane was 40% under 6 MPa with 2 wt % aqueous alcohol solution. PEC membrane separates alcohol over 90% at the same condition above and over 50% even with 20 wt% under 8 MPa. But the flux observed at the latter condition is less than 0.015 mol·m-2·s-1. Therefore, it may be feasible to concentrate up to 15 wt °o of alcohol with the PEC membrane. After 400 hours in operation with aqueous alcohol solution, CA membrane was seriously deteriorated but PEC membranes were not.