The process and application of membrane electrolyzer
The refined concentrated brine solution enters the anode chamber of membrane electron yzer continuously. Under the action of electric field, sodium ions move to the cathode chamber through cation exchange membrane. The sodium ions entering the cathode liquid, together with the hydrogen oxygen ions generated by electrolysis water on the cathode, generate sodium hydroxide, and release hydrogen on the cathode. Chloride ions in salt water solution are limited by the membrane, and can not enter the cathode chamber basically and are oxidized to chlorine gas on the anode. After partial sodium chloride electrolysis, the remaining light salt water flows out of the electrolyzer, after removing dissolved chlorine, the solid salt is re saturated and refined, and then returned to the anode chamber, forming a salt water loop similar to mercury method. Part of sodium hydroxide solution leaving the cathode chamber is used as product, and part of it is added with pure water and returned to cathode chamber. The circulation of lye helps to accurately control the amount of water added, and can take away the heat generated inside the membrane electron analyzer.
Membrane electrolyzer technology has been used in the production of chlor alkali, desalination of seawater and brackish water, the preparation of industrial water and ultra pure water, the purification of enzymes, vitamins and amino acids, the recovery of electroplating waste liquid, and the treatment of radioactive wastewater. Among them, the most widely used and effective technologies are chlor alkali industry. In the chlor alkali industry, chlorine gas, hydrogen and high purity caustic soda (sodium hydroxide) or potassium hydroxide are produced by electrolyzing salt or potassium chloride aqueous solution in cation exchange membrane electrolyzer.