The impact of brine quality on ion-exchange membrane soda production
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This post was last edited by sunjl1981 on 2013-1-6 at 23:47. Hello everyone, I’m a new member here~! I’d like to wish you all a happy New Year first :D! I hope you all enjoy good health, success in your work, and that all your wishes come true...:victory: I’d like to hear everyone’s opinions on the impact of saltwater quality on ion-exchange membrane soda production; I hope you’ll share your insights generously! Thank you in advance :handshake # ， ， &
In ion-exchange membrane soda production, the requirements regarding the quality of brine are primarily aimed at protecting the ion-exchange membranes. These requirements may vary slightly depending on the manufacturer of the membranes and the processes used, but overall they remain the same. It is mainly divided into primary brine and secondary brine; the primary brine removes calcium, magnesium, sulfate ions, as well as organic substances ； Secondary brine is used to remove trace elements, achieving further purification.
The quality of brine mainly affects the ion exchange membrane, with the following impacts: 1. Elements such as Ti, V, Mo, and W form impurity layers on the membrane; 2. Fe also forms impurity layers on the membrane – low levels of it can affect the cell voltage, while high levels can impact current efficiency; 3. Ni forms impurity layers on the membrane, primarily affecting the cell voltage; 4. CaMg causes hydroxide precipitates to form within the membrane, leading to an increase in cell voltage and a decrease in current efficiency; 5. Sr forms crystalline precipitates within the membrane, resulting in an increase in cell voltage and a decrease in current efficiency.
:) Thank you. So, in terms of the concentration of saltwater and pH, what are the most significant impacts on the electrolyzer? :handshake
If the saltwater concentration is low, it mainly causes the ion membrane to delaminate and form bubbles, resulting in a decrease in current efficiency. If the pH of the saltwater entering the cell is high, the water becomes alkaline, which increases the reverse migration of OH– ions and thus reduces current efficiency. On the other hand, acidic saltwater can improve the efficiency of the anode and reduce the dissolution of chlorine; however, acidic saltwater corrodes pipes and equipment, and the iron ions resulting from this corrosion are extremely harmful to the electrolytic cell. Therefore, the saltwater used in the cell is generally slightly alkaline
As for ion exchange membranes, besides factors such as concentration, pH, temperature, and metal ion content, what other aspects related to the quality of saltwater need special attention? :) If any senior has relevant materials, I would appreciate it if you could lend them to me for review. Thank you! :handshake