To provide a practical method for producing hydrogen peroxide by which a heavy-metal compd. contained in an alkaline anolyte is made harmless at the time of reutilizing the alkaline anolyte discharged after an electrolytic reaction in the production of the hydrogen peroxide, high current efficiency and a low cell voltage are kept for a long time and an ion-exchange membrane is hardly deteriorated and suitable for a continuous operation.
An electrolytic cell separated by a diaphragm from a cathode cell and an anode cell is used in this method, an aq. alkaline soln. is made to flow in the anode compartment and oxygen is reduced in the cathode cell to produce hydrogen peroxide. In this case, when the aq. soln. discharged from the anode cell is replenished with an alkali source and reused as an anolyte, the aq. soln. discharged from the anode cell and/or an aq. soln. prepared by replenishing the alkali source to the aq. soln. are brought into contact with activated carbon to reduce the total amt. of iron, chromium and nickel in the aq. alkaline soln. supplied to the anode cell to ≤0.5 ppm.
AOI JUNZO
YAGUCHI TOKIYA
