Study of the optimal electrolysis mode while producing sodium hypochlorite from Mediterranean Sea water

Summary

The theoretical substantiation, as well as the research results of developing the technology for producing low-concentration sodium hypochlorite by direct electrolysis of Mediterranean water for the biocidal treatment of the cooling circuit of nuclear and thermal power plants are presented. The optimal process parameters have been determined. Methods for preventing the formation of cathode deposits have been studied. It has been established that during the electrolysis of seawater with an anode current density of 1000 A/m² the maximum concentration of active chlorine 7.9 g/dm³ can be achieved; whereas at 600 A/m² – up to 6.8 g/dm³ is achieved on iridium-ruthenium-titanium oxide anodes. The current chlorine yield is within 10%. It has been shown that the current chlorine yield and specific power consumption per 1 kg of generated active chlorine reach their optimum values (85–90% and 3–3.5 kWh/kg) at an active chlorine concentration in the electrolysis product of 2 ± 0.2 g/dm³. This determines the process and economic feasibility of producing sodium hypochlorite from sea (ocean) water.

Key words

disinfection , decarbonization , low-concentrated sodium hypochlorite , membraneless electrolysis , inhibition , acid-washing , electrolysis of Mediterranean water