Treatment method for the acidity of brine in the resin tower
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This post was last edited by sunjl1981 on 2013-1-6 at 23:51. While I was working at my previous employer, there was an issue with the acid addition pipeline in unit 1401; as a result, saltwater stopped being treated with acid. Once the problem was fixed, acid addition resumed. However, due to the lag in response of the control valves, the saltwater became acidic. The DCS operators failed to address the system alarm, allowing acidic saltwater to enter the resin tower. It took about 30 minutes before technicians noticed this issue; they then stopped the operation of the resin tower, drained the acidic saltwater, and carried out corrective actions, which prevented more serious consequences. Afterwards, the DCS operators were held accountable for their actions. Let’s discuss the consequences of not detecting it in time. # ， ， &
1. The entry of acidic saline water into the resin tower can affect the treatment efficiency, as well as lead to excessive levels of calcium and magnesium； 2. If this persists for a long time, the serious consequence is that the metal ions adsorbed on the resin enter the saline solution, resulting in excessive levels of calcium and magnesium ； 3. Some people say that under these conditions the resin may undergo a hydrogenation transformation during the regeneration process, but I believe such conditions do not exist: A. The pH value of the acidic solution does not change significantly; especially when it reaches an acidic pH level, the amount of acid required for each change increases by a factor of 10 ； B. In the process design for acidification in brine, a large amount of acid will not enter the brine due to diameter limitations ； C. Acidic saline is not 7% acid, so its eluting effect is not very strong. 4. The above is for reference only; however, such impacts should still be avoided. :lol
If it is not detected and addressed in a timely manner, I believe the following consequences may occur: 1. Excessive levels of heavy metal ions in the brine entering the tank: Regardless of the type of resin used, there are optimal operating conditions, among which pH is a crucial parameter, with 9-11 generally being the ideal range. If the pH is low, the ion exchange capacity inevitably decreases, resulting in an earlier occurrence of breakthrough points ； At the same time, operating under lower pH conditions increases the likelihood of threats from free chlorine or chlorates, which may damage the chemical structure of the resin. 2. Excessive pH value or acidity at the anode inlet: To ensure chlorine purity and anode efficiency, electrolyzer suppliers typically add dilute hydrochloric acid to the saltwater entering the electrolyzer. The amount of acid added is usually controlled manually by monitoring the pH value or acidity of the saltwater exiting the electrolyzer. If this is not detected in time, it will inevitably lead to an excessive pH value at the anode inlet, causing irreversible damage to the sulfonic acid layer and potentially resulting in a severe decline in membrane performance. So the solution proposed by the original poster seems to be quite appropriate:victory:. DCS operators often experience similar issues after adapting to the tense atmosphere of the initial driving phase; this has happened in my own unit as well as in those I’ve worked at before. They become indifferent to alarms, insensitive to changes in data, and uninformed about the situation on site... Therefore, regular training, rotation, and assessments are very necessary
If acidic brine enters the resin column, it will definitely have adverse effects. First, a decrease in pH value leads to a reduction in the adsorption capacity of the resin. This in turn leads to a \"desorption\" phenomenon, during which a large amount of calcium and magnesium ions are washed out of the resin and enter the electrolyzer, contaminating the ion exchange membrane. Furthermore, the presence of chlorates in acidic saline solutions can poison the resin, leading to a permanent decline in its performance.