Depending on the solvent and/or VOC concentration, the adsorption is applied to a system with at least two activated carbon columns whilst maintaining continuous service. The processes uses low pressure water vapour (3 to 4 barg) for the regeneration.
A pre-concentration using a rotary adsorber is necessary for low solvent concentrations in the polluted gas. The effluent to be treated (polluted nitrogen or air) leaves the unit in a purified state, and can be evacuated directly into a discharge chimney or connected to a downstream process, if appropriate.
The adsorbed solvents and/or VOCs are recovered as liquids, during the unit’s regeneration phase. The ultimate residue is the very slightly loaded water that must be settled before being discharged into the environment.
ARKEMA – HUNTSMAN – CHEMICAL – LANXESS – SOLVAY