Membrane pole distance in proton membrane electrolyzers and chlorate decomposition cells
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The high-density natural circulation electrolyzer manufactured by our company, Beihua Ji, has been in operation for nearly five years; it does not have a chlorate decomposition device, and the current chlorate content in the brine exiting the electrolyzer is approximately 17 g/L. I now intend to carry out modifications to the membrane pole distance. Considering the characteristics of electrolyzers with such a membrane pole distance, should a chlorate decomposition unit be installed as well? Thank you!
How to deal with saltwater with such high chlorate levels? With levels this high, it’s impossible to avoid repayment; the electrolyzers need to be upgraded, whether they have a pole distance or a membrane pole distance. Think carefully about the consequences of such high chlorate levels.
As for the destination of the decomposed brackish water, it can either be sent back to the anode liquid circulation tank, or to the anode liquid discharge tank, or directly to the dechlorination tower. Which of these methods is better?
What are the hazards of chlorates to saline systems and electrolyzers?
Mainly, the high level of chlorates leads to intergranular corrosion, which damages the tank frames and gaskets. It also increases the chlorine content in the alkali, causing corrosion in equipment and pipelines with evaporation and concentration systems. Additionally, when the chlorate content in saltwater is high, acid and chlorates react during the regeneration of the resin tower, producing free chlorine that causes resin poisoning.
One more thing: it also affects the solubility of saltwater.
A high sulfate content can affect the saltwater concentration, and a high chlorate content can also affect it; it’s not clear why though I was wondering if there are any materials available for reference?
High levels of chlorates affect the solubility of salts in water; I have learned from this experience. The salt concentration in the brine remained below 300 g/l, and various measures such as raising the temperature at which the salt is dissolved and increasing the height of the salt layer proved ineffective. During an interlock shutdown of the electrolyzer (triggered by a low brine flow rate), it was found that the transmitter in the high-level brine tank was filled with crystallized salt. At that time, the chlorate content in the brine was found to be 20 g/l, so a chlorate decomposition unit was immediately installed. The only way to avoid the use of chlorate decomposition devices is to ensure that sufficient acid is added to the electrolytic cell, thereby reducing the formation of chlorates
I experienced this once: with 305 brine, a large amount of crystallization occurred between the sump and the pipes. Upon analyzing the brine, it was found that only the chlorate level was above the limit. Regarding materials, there is a paper on chlorates in the recent proceedings of the 33rd National Chlor-alkali Industry Technology Conference that you can take a look at. Or find someone who studies chemistry; they can explain this issue.
Chlorate level is too high ------- What is the chlorate content?