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Model ID: 1813

Current Distribution in a Chlor-Alkali Membrane Cell

The chlor-alkali membrane process is one of the largest processes in industrial electrolysis with production of roughly 40 million metric tons of both chlorine and caustic soda per year. Chlorine’s largest use is in the production of vinyl chloride monomer, which in turn is used for the production of poly vinyl chloride (PVC).

Current density in membrane-cell technology has increased dramatically during the last decade as the membranes themselves have improved. This results in lower investment costs for greater production. However, the increase in current density implies an increase in power consumption if nothing is done to dampen the voltage increase. Advances in cell design by increased internal convection, decreased ohmic losses, and better membranes have allowed for large increases in current density with small increases in cell voltage.

This example describes the current-density distribution in a realistic structure for the anodes and cathodes in a membrane cell. This discussion limits the model to one unit cell of the entire cell.

Surface plot of the electric potential, and streamline plot of the total current density.

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