Abstract: Enclosure for separating a component from a gas mixture by adsorption, of the elongated structure type including at least one granular adsorbing product and having a device for introducing and withdrawing gas to ensure a gas circulation in longitudinal direction relative to the enclosure of the elongated structure type. The enclosure is a gas bottle with closed bottom and a cylindrical lateral wall narrowing into a neck provided with an introduction-withdrawing head having a first axial duct extending into a dipping tube reaching at a short distance from the bottle bottom and a second duct opening inside the bottle at the level of the bottle neck. Use for the separation of gas mixtures, such as for the production of hydrogen.