Comparative Studies on Electro-Membrane Processes for Recovery of Ascorbic Acid from its Sodium Salt

This article presents an efficient electro-membrane reactor with three compartments (EMR-3) for in situ ion substitution and recovery of ascorbic acid (ASH) from its sodium salt (ASNa). In situ ion substitution, separation, and recovery of ASH from ASNa were achieved by EMR–3 using the ion-exchange membranes (cation-exchange membranes: CEMs), based on the principle of electro-electrodialysis. Process performances of EMR–3 and electrodialysis (ED) were compared. Under optimum operating conditions for EMR–3 at 3.0 V cm−1 applied voltage (after passage of 3.41 × 103 Coulombs), current efficiency (CE), and energy consumption (W) were found to be 94.3% and 2.63 kWh kg−1, respectively, corresponding to 95% recovery of ASH. While by ED, under the similar experimental conditions, CE and W were found to be 59.1% and 5.44 kWh kg−1, respectively corresponding to 86.3% recovery of ASH. It was concluded that EMR–3 showed high CE, recovery, and low W, in comparison with ED under similar experimental conditions. Thus th...