Bipolar membrane electrolyzer for sodium hypochlorite generation

The objectives of this research work were the construction and evaluation of a laboratory scale electrolytic cell using a bipolar membrane for the production of sodium hypochlorite. The dependence of the cell operation factors on the sodium hypochlorite concentration and specific energy consumption was evaluated, using sodium chloride solutions previously prepared in the laboratory; the experiments were carried out following a factorial design with three levels (3, 4 and 5 V) for the electric potential and sodium chloride concentration (10 and 30 g/L), maintaining a constant electrolysis time of 120 min and recirculation flow of the solutions in both compartments at 350 mL/min. The results showed that the achieved sodium hypochlorite concentration is in the range of (540–1040 mg/L) and power consumption is in the range of (2.1–5.35 kW/kg of NaClO). The sodium hypochlorite concentration and energy consumption were strongly affected by the electric potential applied to the cell, as the voltage increased from 3 to 5 V. In conclusion, this research revealed that this is a promising technology, especially if low concentrations of sodium hypochlorite are used.