Maintenance of ion membranes
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This post was last edited by sunjl1981 on 2013-1-7 00:25. Do Asahi Kasei’s natural circulation bipolar electrolyzers perform better at low current densities or high current densities? Due to weather conditions, the production load cannot be too high; therefore, all electrolyzers are currently operated at low current densities. It is also possible to shut down some of the electrolyzers while keeping the rest operating at high current densities. What impact does this have on the ion membranes of the shut-down and operating electrolyzers? I would appreciate advice from experts :P #hcbbs
Maintenance of the ion membrane in the stopped cell: The membrane should not be completely removed and placed in a balancing solution, as this can lead to the formation of bubbles and pinholes around the area in contact with the gasket. Instead, the cell should be thoroughly cleaned and then filled with high-purity water; the membrane only needs to be moistened once a week. For grooves operating at low current levels, the groove temperature must be strictly controlled.
Thank you. For my question: is it better to turn off some of the slots and run the rest at a high current, or is it better to run them all at a low current?
It is better to shut down some slots and let the rest operate at the rated current. Because as long as the tank is stopped properly, it has little impact on the membrane.
As for whether you should shut down some of the tanks or reduce the load, you need to consider your own situation; if it’s a short period of time, there’s no need to shut down any tanks, but if it’s a longer period, you should shut down a few of them. Another option is that you can calculate it based on the consumption.
We parked for eight days and just started the device. The condition of the ion membrane is okay. The ion membrane was not stored in the tank; instead, the tank was washed and sealed. Submembranous groove preservation causes significant damage to the membrane.
There are certain procedures for membrane maintenance that must be followed. Additionally, operating the membrane at low current levels for extended periods is harmful to it and reduces its lifespan
The protection of ion exchange membranes includes online protection during operation and protection of the membranes after tank removal. Online protection of the membrane requires that, after the electrolyzer tank is sealed, it be circulated and rinsed daily for 1 hour using brine with a concentration of 260–280 g/l at 30–40 degrees, along with an alkaline solution at 26%-28%. If the indoor temperature is very low, the frequency of rinsing should be increased. To protect the membrane after removal from the cell, the electrolyzer is rinsed thoroughly with pure water, the membrane is taken out, and it is stored flat (horizontally or vertically) in a pretreatment solution of 2% NaOH (or 2% NaHCO3) or in high-purity alkaline water with a pH of 11–12.
After the tank stops, circulation is not continued. Replace the wash tank with pure water
Given that the poster only has eight days, from an energy-saving perspective and in terms of the damage to the membranes, it is better to shut down a few units directly and allow the rest to operate at their rated load. For the tanks that have been stopped, they can be sealed as mentioned above, or their condition can be maintained by circulating saltwater in them for 1 hour each day. If the person in charge is still concerned, they can exchange the operating tanks with those that are stopped on the fourth day, in order to minimize any impact. In short, I think the time period is not very long; try not to remove the membrane to avoid any artificial damage. This post was last edited by yzhms on 2008-6-30 18:01]
Asahi Kasei’s ion exchange membranes suffer little impact when operating at over 5 KA, but prolonged operation still affects their current efficiency. After parking, wash the electrolyte tank once a week with water. Unless there is a special reason, do not remove the membrane for maintenance. Removing the ion membrane causes severe damage to it.
Who has pictures of cationic membranes? Please upload them so I can take a look and learn from them
Thank you. Your rank may not be high, but your contributions are significant; I’ve learned a thing or two from you
There are some issues with the claim about the 9th floor. Firstly, the concentration of the circulating liquid should be between 260 and 280 g/L; this is a requirement set by DuPont, and it does cause damage to the membranes produced by Asahi Kasei. Secondly, the membranes must be stored in a horizontal position only, not vertically, in order to prevent wrinkles from forming due to the membrane’s own weight. Third, Kyocera’s films must not be left in high-purity water for long periods, as this will cause them to separate and form bubbles. It’s not clear whether other membranes can be used. The logic should be similar
It is better to shut down some of the cells, while allowing the remaining cells to operate at high current levels – this is better for the electrolyzers and membranes. The electrolyzers that are shut down should be washed with pure water to moisten the membranes
The Asahi Kasei natural circulation bipolar electrolyzers perform well when operated at the specified design current density; it is therefore better to shut down some of these electrolyzers, as operating them for long periods at either low or high currents is detrimental to both the electrolyzers and the ion exchange membranes. The ion exchange membranes of the shut-down electrolyzers should then be properly protected.
A too low current density is not desirable; it is recommended to maintain circulation for a short period of time, while if the duration is longer, it is advisable to drain the system and then fill the main pipe with water to keep the membrane moist.
If the membrane is used for a long time and the planned downtime is short, I think it’s better to operate it at a low current level. This is because the membrane, after being stopped and then restarted, is prone to damage due to prolonged use. Last edited by limingshuguang on 2009-4-25 08:39.]