On the decomposition of chlorates
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This post was last edited by sunjl1981 on 2013-1-7 00:20. In a chlorate decomposition device, what values should be maintained for the ratio of brackish water to acid, as well as for temperature and pH? What are the consequences of adding too much acid? # hcbbs
Our situation: 1. The return flow is an amount of fresh saline water equal to 1/5 of the total amount； 2. The temperature should be maintained between 90 and 95 degrees ； 3. The acidity should be controlled at around 1.5. Adding too much acid is a waste, as it wastes alkali that would otherwise be needed for neutralization before chemical dechlorination.
The amount of chlorate removed by weak brine depends mainly on the chlorate content in the brine leaving the system; it is necessary to take into account the balance of chlorate in the system, with a value roughly ranging from 1/5 to 1/10
The chemical equations for the decomposition of chlorates are: (1) NaClO3 + 6HCl → NaCl + 3Cl2 + 3H2O; (2) NaClO3 + 2HCl → NaCl + 1/2Cl2 + H2O + ClO2. Operational conditions that favor the occurrence of these two reactions preferentially are required. However, only reaction (1) is desired, while reaction (2) produces the undesirable ClO2 gas; therefore, the following conditions are needed to minimize reaction (2): (1) high temperature, (2) an excess of hydrochloric acid at high concentration. Thus, the acid should be added according to the equation above in an appropriate excess amount.
Please refer to the material balance provided by the electrolyzer supplier