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Air | Acid scrubber

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Acid scrubber

Application

Principle

Acid gas scrubbing implies a transfer of volatile components from the gas phase to the liquid phase (acid conditions) with a subsequent neutralisation or hydrolysis of the volatile compound towards a non-volatile compound or salt.

In most cases, sulphuric acid (H2SO4) is used as scrubbing liquid because of its low cost and low vapour pressure. Other acids that can be used are hydrochloric acid (HCl), nitric acid (HNO3), formic acid (HCOOH),…

The scrubber can be operated in a batch mode (e.g. operated with a 10% H2SO4 solution) or with an automated acid dosing control system as a function of a pH-measurement. In the latter case, a refreshment of scrubbing liquid based on the electrical conductivity (EC) is needed in order to prevent salt deposition. 

Under optimal conditions, very high (> 99%) removal efficiencies can be obtained in an acid scrubber for compounds as e.g. NH3, trimethylamine etc. For the scrubbing of compounds like ethylene oxide, multistage scrubbers are provided with removal efficiencies up to 99.9999% or higher.

Scheme

acid scrubber_scheme

Realisations

3-stage acid scrubber for removal of ethylene oxide

2-stage acid scrubber for removal of trimethylamine

3-stage acid scrubber for removal of ethylene oxide

2-stage acid scrubber for removal of trimethylamine