Engineering Chemistry Vol. 13

Abstract: The production of sodium hypochlorite (bleaching liquid) using an innovative electrode design in an undivided continuous electrochemical cell is the main goal of this work. The apparatus consists of two cylindrical concentric electrodes: the cathode is a stainless steel electrode with a diameter of 46 mm and a length of 400 mm, and the anode is a graphite rod with a diameter of 30 mm and lengths of 400 mm and 200 mm. This setup yields an annular column cell. This work investigates the effects of four key process factors on the concentration of sodium hypochlorite (NaOCl) in grammes per litre (g/l) and production efficiency: anode length, flow rate, current, and sodium chloride (NaCl) concentration. In a typical experimental setup, the following electrochemical cell characteristics are obtained with an anode length of 200 mm, a current of 8 A, a flow rate of 100 ml/min, and a NaCl concentration of 75 g/l: NaOCl concentration of 3.5 g/l, energy consumption of 2.2 kWh/kg, efficiency of 95.5%, capacity of 15.1 mol/m2.h, and space-time yield (STY) of 746 mol/m3.h.