Electrodialysis in water-ethanol solutions: Application to the acidification of organic salts

Up to now, most electromembrane processes have been performed in aqueous media. Here the feasibility of conversion of sodium salts of organic acids (propionic, butyric and octanoic) was demonstrated in water-ethanol media up to 50% v/v. The alcohol content was the same in all the electrodialysis compartments, and the conversion ratio remained high for sodium propionate and butyrate at 10 and 30 mA.cm(-2). When the length of the linear hydrocarbon chain was increased to sodium octanoate, the conversion ratio was less than 50%. The main interest of using ethanol-water media is the increase of organic acid solubility.