Hydrina® process

A second Hydrina process involves recovery and recycle of caustic soda and a mixed solution of Na2S04 and H2SO4. This is similar to the two-compartment cell of Fig. 15.18, but it uses the hydrogen-depolarized anode instead of the conventional type. A third version uses a three-compartment cell with the hydrogen anode [106,107]. Saturated Na2S04 enters the central compartment, and water is added to the electrode compartments. The products are sulfuric acid and caustic soda of high pmity. 

---