Abstract: The gas which is to be dried is fed into an absorber (1) where it is brought into contact with a glycol in countercurrent. The glycol absorbs the moisture from the gas and impurities. The glycol laden with water and impurities is removed from the absorber (1) via a line (5). It is then regenerated in a reboiler (9) where the water is eliminated by heating. The water-free glycol is passed into a storage vessel (10) from which it can then be refed to the absorber (1). The glycol which is withdrawn from the storage vessel (10) is purified by mixing it with at least half the quantity of water. The mixture is brought to a temperature above cloud point where it is maintained for a predetermined length of time so that the impurities flocculate. The flocculated impurities are removed in a filter (18) arid the purified glycol mixed with water is refed to the reboiler (9) via a line (19). The drying process is very economical as it integrates environmentally-friendly and simple purification of the glycol.