Eliminate SO2 emissons 1

[Duff44]

We have to eliminate NaOCl with Na2SO3 and after that, we have to keep an excess of 0.1% Na2S03 because we have to lower the pH from 13 to 2 with HCl 36% p/p (currently use in the plant)in order to tranfert the solution to and other part of the plant which have a HAC removal process. When we insert the HCl, we have a SO2 emanation at the stack. To eliminate this SO2, we want to inject H2O2 30% p/p before injecting the HCl, when we do so, we are suppose to have an O2 emanation at the stack. We still have SO2 emanation. We were suppose to use approximately 25 l of H2O2 for a solution of 80 m3 which have a 0.1% Na2SO3. We have use 40 l of H2O2 but we still have SO2. Is H2O2 the right choice or an amine solution would be better. We have to eliminate SO2 to atmosphere.

 

[mbeychok]

Duff44:

You did not tell us the SO2 emission flow rate. Assuming that it is a rather small amount, I would recommend that you route your gaseous emissions through a simple scrubber using a 15 or 20 weight percent aqueous solution of NaOH.

Since NaOH is fairly expensive and the spent NaOH would not be regenerable, it would be quite costly to use it for a large SO2 flow rate. Do the math and see if it is affordable for your situation.

Milton Beychok
(Visit me at www.air-dispersion.com)
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