REGENERATION OF HYDROCHLORIC-ACID AND SODIUM-HYDROXIDE WITH BIPOLAR MEMBRANE ELECTRODIALYSIS FROM PURE SODIUM-CHLORIDE

In this work an electrodialysis process with bipolar membranes was use d to generate HCl and NaOH from pure NaCl and Algerian rock salt from Hamraya. The current efficiency of this process was limited by the pro ton leakage through the anion exchange membrane: diffusion of HCl, NaO H, Na+ and Cl- through bipolar membranes. In this work two low-proton- leakage membranes, AAV and ACM, were used. NaOH and HCl solutions of h igh purity were obtained. The experimental values of the HCl and NaOH fluxes are compared with the values that could be calculated after int egrating the Nernst-Planck electrodiffusion equations. This calculatio n required several parameters that were experimentally determined: ion diffusion coefficients, membrane conductance and amount of sorbed ele ctrolytes.