Long-term operation of ion-exchange membrane cells
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What are the hazards associated with long-term cycling (more than 4 hours) during the shutdown process of ion membrane electrolyzers?
During long-term shutdown cycles of the electrolyzer, it is necessary to properly control the concentration of alkali in the cathode chamber
Alkali concentration is normal, above 28%
More than 4 hours, what is the maximum time?
Asahi Kasei requires it to be no more than 8 hours; I suppose it’s due to the galvanic cell reaction.
It should be this one. I’m not sure if there are any other aspects
The main considerations are, first, that water migrating to the cathode chamber within 8 hours reduces the concentration of circulating alkali, but it does not drop below 28%; second, issues that cannot be resolved within 8 hours cannot be solved in a short time either, so the tank is drained and washed. Our facility once maintained a parking cycle of 10 hours, and the electrolyzer was not affected in any way, as long as the tank temperature and catholyte concentration were maintained.