Discussion on the outlet temperature in ammonia-based desulfurization
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Regarding ammonia-based desulfurization, there are issues such as ammonia escape, decomposition of the products, and white mist. In the calculations related to the reaction process, I believe that to address these problems, it is necessary to focus on preventing ammonia escape. I think a desulfurizing agent can be prepared by mixing ammonia water at a concentration of 5% with ammonium hydride solutions. Increase the spray volume to reduce the NH3 partial pressure. 8 b9 J7 G) Y" |+ i9 Q In that case, the outlet temperature of the desulfurization tower will be around 45 degrees only. Can such gas be discharged directly? Please give me some advice.
The ammonia-based desulfurization method has high efficiency; especially at temperatures below 23 °C (with a desulfurization rate of over 99.15%), and when the temperature is around 60 °C, the desulfurization rate for the main desulfurization reactions is also above 98.15%. From a kinetic perspective, the activation energy for the ammonia-based desulfurization reactions is low, so no particularly high reaction temperature is required. Therefore, taking into account both the thermodynamic and kinetic properties of these chemical reactions, it is recommended that the reaction temperature for ammonia-based desulfurization be maintained around 60 °C.
The temperature of the gas exiting the ammonia-based desulfurization process is generally only related to the temperature and moisture content of the flue gas entering the system.
This issue should be understood as follows: 1. The acid dew point of SO2 is around 50-60°C; therefore, the outlet flue gas temperature is generally also around 50-60°C； 2. During the actual calculation, a temperature can be set; the amount of water that can evaporate is determined based on the heat relationship, and the amount of water that can evaporate is also calculated using the humidity of the incoming flue gas. These two values should be similar to each other; if there is a large difference, the temperature setting should be adjusted, and the process should be repeated iteratively ； 3. The control of ammonia escape has little to do with whether ammonia water or liquid ammonia is used. The main thing is to choose the right ammonia addition point. At the same time, to control ammonia escape, it is necessary to reduce the ammonia partial pressure, as well as to control the ratio of ammonium sulfite to ammonium bisulfite in the solution. This is directly reflected in the pH value. Generally, control at 5-6
Around 60 ℃ is better! We’ve all gone through the tests! At low temperatures, its activity is low, so less natural ammonia is released; but due to the reduced activity, the reactions proceed slowly as well!
It is possible to argue about the disadvantages of having a flue gas temperature of 80°C after it has been exhausted Thank you!
45 degrees definitely cannot be discharged directly
45~50. I worked on a few ammonia-based projects, and the temperature was 47 degrees