| Abstract: | Permeation and separation characteristics for aqueous alcoholic solutions through a modified silicone rubber membrane containing poly(propylene glycol) in the polymer chain were studied by both pervaporation and evapomeation. Both the permeation rates in pervaporation and evapomeation increase, and the selectivity for ethanol in pervaporation does not change but that in evapomeation increases with an increase in the permeation temperature. When the temperature in the membrane surroundings was kept constant and the temperature of the aqueous ethanol solution was varied, or vice versa, it was found that the permeation rate and the permselectivity for ethanol are significantly influenced by the temperature in each permeation condition. The selectivity for alcohols through the modified silicone rubber membrane in the evapomeation method with control of the temperature difference decreases in the order methanol > ethanol > 1-propanol. |
