What is the typical ammonia-to-sulfur ratio in ammonia-based desulfurization?
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In ammonia-based desulfurization, is there a parameter similar to the calcium-sulfur ratio in the calcium method, such as an ammonia-sulfur ratio? If so, what is its typical value? This post was last edited by chaochao on 2008-7-11 08:15
There is no certainty. It mainly depends on the amount of chloride ions entering the system. If chloride ions are not taken into account, a value of 2.01 can generally be achieved
The ammonia method generally doesn’t consider this; if this value is needed, I think 2 will suffice
Going back upstairs, 2 is not possible; theoretically it could be 2, but ammonia escapes as well. The ammonia content in the exhaust gas is generally around 10 ppm. In addition, chloride ions and fluoride ions in the exhaust gas also consume some of the ammonia.
Ammonia-based sulfur dioxide removal is problem-free, so there is no such concept as a \"calcium-sulfur ratio\"; however, the ammonia method has the issue of ammonia escape. Therefore, controlling the addition of ammonia is a challenge
It is necessary to monitor different desulfurization conditions as well as the ammonia concentration at the tail end
The utilization rate of ammonia in ammonia-based desulfurization depends on 1) the control of the ammonia concentration in the flue gas, and 2) the oxidation rate of ammonium sulfite.
Oxidation rate of sulfurous acid an. I don’t think this indicator is very meaningful; firstly, it’s difficult to measure and not accurate. Second, it is sufficient as long as the ammonia escape rate can be controlled
The oxidation rate is difficult to measure, but if oxidation is inadequate, the ammonia smell in the ammonium sulfate plant will be very strong and can be detected quite easily. Like many ammonia-based desulfurization and ammonium sulfate drying plants in the country, they have a pungent ammonia smell. The oxidation rate is not about determining a specific value; rather, it is achieved by selecting appropriate process parameters such as pH control, slurry concentration control, oxygen-sulfur ratio, and slurry residence time, in order to ensure a high oxidation rate – generally above 99%.
I’ve never heard of the sulfur-to-ammonia ratio in ammonia-based desulfurization; however, the S/C ratio is something that is often mentioned. If the desulfurization effect is good, the optimal range for S/C is considered to be between 0.7 and 0.85.
The S/C value is used to control the concentration of (NH4)2SO3, as it is an effective desulfurization absorbent. Theoretically, when S/C is 0.5, the partial pressure of NH3 becomes infinite, resulting in significant ammonia escape. Therefore, it is necessary to control the S/C value; in practice, this means controlling the pH of the absorption solution at 5-6