How to improve the current efficiency of expanded anode-modified membrane electrolyzers?
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This post was last edited by sunjl1981 on 2013-1-6 at 19:58. The 30-Ⅲ type metal anode electrolyzers in our plant (a total of 80 units) underwent an expansion anode modification in 2007; they have been in operation for two years now. Based on the performance over these two years, the operating current is 54 KA, and the average cell voltage has decreased by 0.16 V. However, the concentration of the electrolyte is low, with the concentration in the main pipes being around 110 g/l. The age of the cells is 6–7 months. The most significant issue is the low current efficiency, which is only 89%. Our plant uses a membrane filtration process for the saltwater used in the electrolyzers, and the calcium and magnesium content in the saltwater entering the cells is below 1 PPM; the saltwater used is alkaline. I would appreciate suggestions from colleagues in the industry on how to make improvements # ， ， &
It’s probably a problem with membrane adsorption or baking. The technology provided by the manufacturer isn’t satisfactory either; there is a high flow rate at the cathode and a low alkali concentration. It takes a long time for everything to function properly. Although the cell voltage can be reduced by more than 1 volt, the low alkali concentration causes problems in the evaporation process – less alkali is produced, and more steam is consumed. It’s not cost-effective at present. I think the technology isn’t mature enough: funk:
In my opinion, the main reason is an issue with the adsorption by the membrane; lower the operating liquid level and check the alkali concentration in a single tank
The Type 30-Ⅲ metal expansion anodes used in our factory, together with modified diaphragm electrolyzers, have been in operation for three years now. Due to the economic downturn, the operating current is 35 KA, and the concentration of the electrolyte in the main tank is around 116 g/l, which is better than that in your factory. . The current efficiency is fairly good at 94.5%, but the liquid level is a bit low (almost half of it – only 135 mm). However, the situation in your factory is a bit special; with such high current levels yet such a low efficiency, it’s very likely that the membrane isn’t adsorbing properly.
Dear friends, please share your valuable opinions after reading it
135mm？ Is membrane permeation slow? What is the amount of single-tank brine to add?