ANALYSIS OF THE SODIUM LACTATE CONCENTRATION PROCESS BY ELECTRODIALYSIS

Electrodialysis is an interesting technique developed for recovering a nd purifying salts and acids from fermentation broths. In this work th e concentration process of sodium lactate solutions was analyzed using a two-compartment electrodialytic unit equipped with commercial membr anes (Neosepta AMX and CMX, Tokuyama Soda). The influence of several o perating parameters on the overall process performance was investigate d. For instance, it came out that at low current density values such m embranes are able to operate a perfect separation of opposite charges, resulting in a good process performance. Moreover, water transport by electro-osmosis has to be considered, hence lowering the stack perfor mance. Lastly, the reliability of a general mathematical model for thi s process was tested. The consistency between experiments and model re sults is fairly good, allowing the use of this model for design and op timization purposes.