Cationic membranes for phenols production

Ionic Substitution by Electrodialysis is a good alternative to the industri al conversion of sodium salts of phenols into undissociated phenols, conven tionally performed through acidification by strong acids. The acidification through electromembranes combines the possibility to achieve high conversi on values with the advantage of keeping the process stream separated from t he acid stream. The process is performed through cationic membranes; conver sion can be obtained also in the absence of electric current, even if sligh tly better performances can be achieved by applying an electric field. Proc ess feasibility as well as membrane resistance is tested, for the case of m odel solutions reproducing the main features of the real process streams. M aximum conversion and process rate are greatly affected by the ratio betwee n protons in the acid solution and sodium ions in the process solution. Phe nol losses into the acid stream and chloride contamination of the process s tream can be reduced by working with diluted process and acid streams.