Factory

The chloralkali industry is one of the largest electrochemical operations in the world, the main products being chlorine and sodium hydroxide generated simultaneously by the electrolysis of sodium chloride solutions. The chloralkali industry serves the commodity chemical business, chlorine and sodium hydroxide (also called caustic soda) being indispensable intermediates in the chemical industry. In the membrane-cell process, sodium chloride brine is fed to the cell and distributed equally among the anode compartments, while water fed into a second header flows into the cathode compartments or into an externally recirculating stream of catholyte.The depleted brine, or anolyte, overflows with the chlorine gas into an anolyte header and the caustic soda liquor overflows with the hydrogen gas into a catholyte header.The membrane cell produces about 35% caustic soda, which is concentrated by evaporation to 50%. Membrane cell caustic soda is the preferred product compared to the diaphragm and mercury-cell caustic soda.