Exploring the Production of Sodium Hydroxide via Bipolar Electrodialysis from Sodium Carbonate Solutions

Abstract

This study explores the production of sodium hydroxide via bipolar electrodialysis using MB-3 membranes and a laboratory electrodialyzer-synthesizer with a three-chamber unit cell (five elementary cells, active area of each membrane 1 dm2). The research compares the use of sodium carbonate and sodium sulfate as initial solutions. The results show that sodium carbonate leads to a higher concentration of the resulting alkali under comparable process conditions. The alkali current efficiency is more than 70% when using sodium carbonate, while it drops sharply to 0.4–0.5 when using sodium sulfate. The energy consumption for transferring one kilogram of alkali ranges from 2.8–13.9 kWh/kg at operating current densities of 1–3 A/dm2.