The issue of dechlorination surcharges
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:After a single shutdown of the electrolyzer and upon restarting it, the amount of chlorine removal and acid added increased by more than one-third, almost by half; of course, more alkali was also added as well. No significant change was observed in the pH of the brine coming out of the electrolyzer. Could you tell me from which aspects I should start investigating?
I’m not sure where the battery in question is located. If no dechlorination or acid addition has been done to the battery solution, it means that side reactions in the anode solution are increasing! A problem occurred with the membrane during this shutdown, resulting in a decrease in efficiency! Mainly, the hydroxide backflow has increased! Also, please rule out high pH of the brine entering the tank, as well as the presence of concentrated brine in the fresh brine exiting the tank, such as when valve 85 is not properly closed!
Agreeing with the view above, I would like to add that no significant change in the pH of the effluent may be due to damage to the ion exchange membrane in a single cell; a analysis of that specific cell can be conducted. Could the increased amount of acid used in the deacidification process be caused by an excessive amount of chlorine-containing water? (I’m not sure which type of tank the poster is using; I’m referring specifically to those made by Asahi Kasei.) It could be the chlorine-containing water that comes from the vacuum pump used in the chlorohydrin treatment process to produce dihalides.