To produce sodium hypochlorite with 15% available chlorine, what concentration of alkaline solution is required to meet the production requirements? The production temperature is 35 degrees, and the finished product contains 1% residual alkali.
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The production temperature is 35 degrees. To produce sodium hypochlorite with 15% available chlorine and 1% residual alkali, what amount of alkali in grams per liter is required in the solution? How is it calculated? I hope some expert can give me some advice! It’s better to have both pictures and articles for learning*; thank you
15% liquid caustic; free alkali after chlorination <1, with the effective chlorine content of the product being around 12-13.
At a temperature of 20–25°C, 21%-21.5% of alkali is sufficient; at 35°C, side reactions become significant, so around 23% of alkali may be required
During the later stages of hydrosodium production, it is advisable to keep the temperature below 20 degrees, and to ensure that the residual alkali level does not exceed 1%; this will help maintain the stability of the hydrosodium solution, facilitating its storage and transportation. At higher temperatures, side reactions become very apparent; once these side reactions continue, the acidity of the sodium hypochlorite solution increases, which in turn accelerates the decomposition reactions, leading to a significant drop in the concentration of effective chlorine. This is a vicious cycle of reinforcing side reactions. This is why the 84 disinfectant in your home gradually loses its effectiveness
Regarding your question, the amount of alkali solution (g/l) = effective chlorine (15%) × temperature (35 degrees) × residual alkali (1%) / total water content. The total water content is equal to the weight of the materials used (g) + the amount of water added (g). The weight of the materials including the added water is determined based on the raw materials used and the desired mass of sodium hypochlorite in the final product. For example, if the weight of the material fed in is 100 grams and the amount of water added is 200 grams, then the total moisture content is 300 grams. The concentration of the alkali solution (g/l) = 15% × 35°C × 1% / 300 = 0.0925 g/l.