Reductive scrubber

Application

• Removal of halogenated compounds:

  • bromine (Br₂)

  • chlorine (Cl₂)

• ...

Principle

Reductive gas scrubbing usually implies a transfer of volatile components from the gas phase to the liquid phase (water) with a subsequent chemical reduction of the dissolved compounds. This reduction is most often realised using sodium bisulphite (NaHSO₃) as a reductant.

Reductive scrubbing can be done in batch operation if the expected input of volatiles is well known. For most applications, however, the chemical dosing is done based on an automated control of both the redox (ORP) and the pH value of the scrubbing water. Control of the pH is crucial in order to optimise kinetics, minimise chemical consumption, prevent chemical depositions and minimise the emission of unwanted compounds. Next to that, a refreshment of scrubbing liquid based on the electrical conductivity (EC) is needed.

Scheme

Realisations