Abstract: An adsorber system wherein an air/vapor mixture is alternatively fed to a pair of functionally interchangeable adsorbers and the vapor is removed from the air in one of these adsorbers while the other adsorber is subjected to regeneration with steam, and the two adsorbers are then functionally interchanged so that the regenerator adsorber recovers vapor from the mixture and the other adsorber is then subjected to steam regeneration. An adsorber to be regenerated is connected to an adsorber operating to remove vapor from the mixture at one side of the adsorber to be regenerated and steam to the adsorber to be regenerated is admitted from the other side thereof, thereby driving air containing vapor from the adsorber to be regenerated into the other adsorber.