Organic Acid Separation Through Electrodialysis

The use of bipolar electrodialysis to acidify salt solutions has proven a valuable technique in organic acid production. However, the need to concentrate generated acids from aqueous solution has resulted in the development of separation procedures that are costly and complex. One method for simplifying this process is to design a system in which organic salts can be acidified and removed from aqueous solution simultaneously. In this study, we present a system capable of concentrating, acidifying, and removing organic salts from solution through the use of ionic liquids. Our system used a bipolar electrodialysis system operating in batch mode with ionic liquids in the concentrate steam and sodium butyrate as our organic salt. The desired organic products were moved to the ionic liquid phase through electrodialysis and then distilled from the concentrate solution. Since ionic liquids possess no measurable vapor pressure, our organic acid was recovered at a much higher purity than through traditional distillation with water. This system also required 40% less energy in order to separate our organic salt when compared to current refining techniques. The implementation of this electrodialysis procedure in existing organic acid production facilities has the potential to severely reduce energy consumption and production costs.