ELECTRODIALYSIS OF HYDROCHLORIC-ACID

Electrodialysis (E.D.) was not commonly used for the extraction and th e reconcentration of acids because the standard anion exchange membran es (A.E.M.) are highly permeable to proton. Recently, special A.E.M. s howing a reduced proton leakage have been developed for the recovery o f acids by E.D. In this paper, we present a study of E.D. of hydrochlo ric acid solutions using one of these membranes. The two main paramete rs which quantify the performances of the process: the current efficie ncy of HCl removal and the maximum reconcentration level of the acid a re analysed on the basis of a transport model. The current efficiency is only determined by the proton leakage through the A.E.M. while the maximum reconcentration level is also determined by the water transpor t through the two ion exchange membranes.