How to solve the scaling problem caused by liquid alkali in flue gas desulfurization scrubbers
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Flue gas desulfurization scrubber: alkali solution is used for desulfurization; how to address the scaling problem caused by liquid alkali?
The last edit to this post was made by Desert Fish on 2016-11-16 at 10:06. This issue needs to be considered from multiple aspects: 1. Whether the concentration of liquid caustic soda is too high or too low； 2. Is the return flow rate of liquid caustic appropriate? ； 3. Is the dust concentration in the flue gas too high? ...There are many more factors that can be compared using this approach!
Is there a relationship between the concentration of liquid caustic and temperature?
Additional note: 1. The make-up water used in the wet scrubbing desulfurization process is also quite important. Whether condensate water from the plant area, rainwater, or snowmelt is used, as long as parameters such as hardness, Cl-, and COD are within acceptable limits, it can be used as make-up water. On the other hand, if the hardness is high, scaling is likely to occur. Furthermore, when the pH control is set high, for example at pH=10, scaling due to CO2 absorption is likely to occur.
In my opinion, the relationship between alkali concentration and temperature is mainly related to the crystallization of the alkaline solution; the focus should be on the pipes carrying the alkaline solution rather than the system’s overall pipelines, that’s my personal view.
Isn’t scaling in the system pipelines?
If it’s an alkaline solution, corrosion does not occur; increasing the flow of liquid inside the pipes or using backflow can help. In the case of desulfurization slurry, it is necessary to increase the frequency of checks on the slurry density, and to strictly control this density by adjusting the flow rate of the liquid fed into the wastewater treatment system
That’s right; what I’m saying is that the relationship between alkali concentration and temperature has nothing to do with scaling.
Circulating the alkaline solution will yield much better results
We have not encountered any scaling issues when using liquid caustic to absorb sulfur dioxide; however, we have seen crystallization of the liquid after absorption, and we are still working on addressing this issue
Scaling is also related to the surface polishing quality!