I would appreciate everyone’s advice on the reasons behind the increase in slot voltage
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Hello everyone. Recently, the tank voltages of three systems in our facility have increased. The parameters of the secondary refined brine are normal; the analysis results are as follows: calcium at 5.42, magnesium at 2.07, strontium at 0.53, barium at 0.11, manganese at 0, iron at 3.19, aluminum at 1.27, nickel at 0, and the organic matter level at 12.2. The operating pressure, pressure difference, and temperature of the electrolyzer are normal, and the production volume is normal. The analytically pure water meets the requirements for make-up water, and the parameters such as sulfate and chlorate in the saline are within normal ranges. It is preliminarily assumed that there is a problem with the raw salt, but there are no clear indicators to prove this. Please help analyze what other factors could cause an increase in tank voltage. I am extremely grateful
Organic matter analysis result: 12.2. ----Apart from being slightly high, there are no issues with the other indicators
How many systems are there for primary brine? Conduct a comparative analysis of the changes in the parameters of primary brine. Additionally, since there is suspicion that there might be problems with the raw salt, have there been any changes in the analysis parameters of that raw salt? It’s also possible that the brine produced undergoes contamination, resulting in higher levels of COD, TOC, BOD, etc.; such issues are difficult to detect through standard analysis methods. Generally, when a new system is put into use, it can cause systematic contamination of the brine. Also, check whether the high-purity acid added contains excessive amounts of calcium and magnesium. I’m not familiar with the detailed manufacturing process; these are just my personal opinions.
The saline sample should be sent to other affiliated institutions for analysis and comparison, to see if any issues were detected.
There is an increase in the voltage of just one cell; there are no trends in standard voltage or current efficiency, nor any information regarding start-up or shutdown operations. Although the analysis of the brine shows no problems, simply an increase in cell voltage alone isn’t enough to allow anyone to draw any conclusions, after all, the brine data isn’t real-time data! Send me the voltage values for each cell in your battery pack, as well as any recent changes in voltage, so I can take a look! Also, it is necessary to ensure that the hydrochloric acid used in electrolysis is of good quality; it would be best if you could send a picture of the membrane in use for inspection!
The increase in cell voltage is related not only to the quality of the brine but also to the temperature of the brine fed into the cell, the amount of acid added, and the weather conditions. A lower temperature of the brine fed into the cell leads to an increase in cell voltage, as does a reduced amount of acid added. The rise in cell voltage is a complex issue that requires consideration of various factors. If the voltage decreases again after some time, it is likely due to temperature or the amount of acid added; however, if it does not decrease, it can cause permanent damage to the membrane, and this is related to the quality of the brine, pure water, and hydrochloric acid. It is important to strengthen monitoring, and I hope to hear about the reasons for the increase in your cell voltage soon.
There are various reasons for an increase in cell voltage; it is possible to conduct a comparison with brine samples from other chlor-alkali manufacturers to check if there are any issues with the brine. The voltage of individual cells should also be measured and compared; if the voltage of a particular cell increases, it might be due to a low flow rate of brine into that cell.
Thank you for your suggestion; I’ve gone out to do a comparative analysis