Electrolyzer design and process optimization for electrochemical synthesis of high‐purity sodium hypochlorite solutions for biomedical applications

BACKGROUND Technologies and preparations that provide a fast and powerful microbicidal effect are vital for the prevention and treatment of infections. Active chlorine compounds, especially sodium hypochlorite (NaOCl), play an important role both as pharmaceuticals and as disinfectants. However, the stringent requirements for biomedical solutions do not allow the use of most traditional technologies for their synthesis. The paper describes the concept, architecture and individual components of an electrolyzer and its optimal operating parameters for obtaining high‐purity NaOCl preparations. RESULTS The synthesis of target NaOCl solutions is expediently carried out by electrolysis of approx. 9.0 g L −1 NaCl solutions in original flow cells with a coaxial arrangement of electrodes. The optimal anode is a titanium tube with a catalytic RuO 2 –IrO 2 coating. The cathode should be made of smooth titanium or of heat‐treated platinized titanium. The initial electrolyte must be fed into the cell using a peristaltic pump. At a current load of 2 A and the use of two series‐connected cells, the proposed technology ensures the production of 8.7 L h −1 of a solution containing 500 mg L −1 NaOCl and less than 1.0 mg L −1 NaClO 3 . An electrolyzer with three flow cells allows for the continuous production at 9.2 L h −1 of a 1000 mg L −1 NaOCl solution containing no more than 6 mg L −1 NaClO 3 . CONCLUSION NaOCl solutions obtained by the proposed technology have characteristics that allow their safe biomedical applications. Experience in their industrial production and biomedical use confirms the correctness of the concept and the high reliability of the developed electrolyzer. © 2025 Society of Chemical Industry (SCI).