Production of sodium hypochlorite in an electrolyser equipped with a ceramic membrane

The electrochemical synthesis of sodium hypochlorite in a membrane electrolyser equipped with an alumina-zirconia ceramic membrane and comprising a titanium anode coated with cobalt oxide has been investigated. The current density, sodium chloride concentration and solution flow velocity in the electrode chambers of the electrolyser have been measured in order to establish how these parameters effect process efficiency. It was found that under optimal conditions the electrical current efficiency reaches 77%. An electrical energy expenditure of 2.4 KWth and a sodium chloride consumption of 3.1 kg per kg sodium hypochlorite produced have been recorded. The anti-corrosion stability of the anode under various experimental conditions was also studied.