Steam Desorption

Whatever the solvent recovery process used, it is reliant on the input of energy to affect the ‘desorption’ of the solvent (adsorbate). Usually the most abundant reliable heat source is low pressure dry steam, which can be fed to a solvent saturated bed of activated carbon (usually in downflow) to volatilise and drive the desorbed solvent to ancillary equipment (decanters or distillation) for separation from the condensed steam. Often this solvent can return immediately to the process in which it was originally in use. After steaming, the carbon bed is then dried and cooled to await inflow of solvent laden air. Usually multiple adsorbers are used so that the process can continue uninterrupted.