Electrodes for industrial chlorination: key requirements

The chlor-alkali process simultaneously produces chlorine, caustic soda and hydrogen by electrolysis of brine. It is one of the oldest and largest industrial electrochemical processes in the world (~75 Mt/year of Cl₂).

Electrode requirements

• High selectivity: minimise co-evolution of O₂, which generates contaminated Cl₂ and degrades the anode.
• Chemical resistance: operate 15+ years in saturated brine with variable pH.
• Mechanical stability: no deformation under startup/shutdown cycles.

Jolt chlorination electrodes (the SPARKFUZE™ CL-A range) use mixed RuO₂/IrO₂ coatings on titanium, optimised for >99.5% selectivity in continuous operation. They are already deployed in industrial and municipal plants.