Desulfurization of flue gas 1

[soufiane]

To absorb SO2 content in the smokes of combustion one can NaOH utliser dissolve in water. Would I want to know the possibility to use the water of sea with NaOH instead of the soft water?

 

[bimr]

You probably could do it, but it would not be economical. You would be limited by the solubilities of the various compounds such as calcium sulfate.

In a typical FGD, you have a recirculating loop. Because of the higher dissolved solids in seawater, you probably could not recirculate. To maintain the maximum solubilities, you would probably have to add chemicals on a once through basis. That would not be economical. It also goes without saying that the equipment cost would also be expensive because you would have to use materials that would stand up to seawater.

 

[siretb]

It is possible to use sea water,alone (no NaOH) to scrub SO2 and this can be economical (near the sea of course). usual designs are one-thru.
this sea water FGD is used on a commercial basis.

 

[cub3bead]

There is usually sufficient alkalinity in the seawater to neutralize absrobed SO2 for once though operation without chemical addition. Permitting a plant using this technology would be unlikely in North America, Japan and Europe but possible other regions.

Using NaOH for a scrubbing reagent is too expensive unless you recover the sodium fraction for reuse/recycle to the absorber by reacting it with limestone external to the scrubber.

 

[Fizzhead]

Soufiane:

Both once through seawater scrubbing and sodium based scrubbing technologies exist and particularly the sodium based system has been highly developed by several vendors. I suggest you try to contact someone like Foster Wheeler, or Combustion Engineering to see what they can tell you about their technologies. Also, you might want to check on the possibility of patent infringement before you go too far with anything.