Sodium hypochlorite can be produced by reacting chlorine and sodium hydroxide solution. It can provide a by-product from the chlorine vented when organic chlorination is carried out. The ATR ASAHI plant carries out a batch operation and the required quantity of sodium hydroxide solution is charged to the recycle tank and circulated around the reaction column. The reaction column incorporates a packed section to contact the sodium hydroxide and chlorine, together with heat exchangers to remove the heat of reaction. The plant will produce sodium hypochlorite solution containing 14-15% available chlorine corresponding to approximately 16% by weight of sodium hypochlorite.
A typical production rate is 11 tonnes/ 8hour batch, which is obtainable from a 300mm (12in) nominal bore column.