Abstract
We investigated a novel technique for the production of pure-carbonated water using bipolar membrane electrodialysis accompanied by a chemical reaction. The electrodialyzer was composed of Feed, Strip, and Electrode compartments, which were divided by bipolar and cation-exchange membranes. A sodium carbonate aqueous solution was injected into those compartments. When a voltage was applied to the electrodialyzer, hydrogen ions were generated by water splitting in the bipolar membrane, and produced carbon dioxide by means of chemical reaction with the carbonate ion. The sodium ion also simultaneously moved from the Feed to Strip compartments. Consequently, pure carbonated water was produced. However, generation of carbon dioxide bubbles was barely observed during electrodialysis under the condition of 10 A/m2. These results suggest that generation and absorption of carbon dioxide gas occur mainly in the bipolar membrane.
