Designing a high-efficiency hypochlorite ion generation system by combining cation exchange membrane aided electrolysis with chlorine gas recovery stream

Clean water is an absolute necessity to sustain life on Earth; thus, research and development in water management and disinfection processes are necessary. As an effective method to disinfect water, dilute solutions containing hypochlorous acid and hypochlorite ions are often utilized. Herein, we report a newly designed hypochlorite ion generation process, which involves installation of cation exchange membranes (CEMs) to conventional electrolysis cell to enhance stability and controllability, and addition of Cl2 recovery stream to increase the production rate and efficiency of hypochlorites generation. Electrolysis cells with SPEEK, Nafion 115, and Nafion 324 are evaluated and compared with a cell without CEM, which resulted in up to 17% enhancement of the production rate. In addition, increased energy efficiency and controllability of the electrolysis process are achieved when SPEEK is used as the membrane. The CEM installed electrolysis combined with Cl2 recovery stream, which enables enhancement of stability and performances of the electrolysis-based hypochlorite generation, opens a new possibility for an efficient in-situ water disinfection system. [Display omitted] •CEM aided hypochlorite electrolysis process is designed by adding Cl2 recovery.•This process allows controllable OCl− generation with broad concentration range.•Up to 17% enhancement in hypochlorite production rate is achieved.•With SPEEK as CEM, energy efficiency of the process has increased.•It can be applied in on-site/in-situ hypochlorite generation with optimization.