to a first adsorbent zone for contacting with a first adsorbent effective in the adsorption of water by flowing the air in a direction within the first adsorbent zone parallel with the axis of the first adsorbent zone to form a dry gas flowing the dry gas from the first vessel to a second adsorbent zone comprising a second adsorbent disposed in a radial arrangement about the same axis to remove carbon dioxide regeneration of the adsorbent beds may be carried out independently application_number US 42202495 A description referring now to fig1 and the preferred embodiment wet feed air from a compressor not shown at a pressure between about 50 and about 250 psia is flowed in stream 10 to inlet connection 4 on the vessel 2 containing a first adsorbent bed preferably vessel 2 is cylindrical and of constant diameter about a center axis or may alternatively be of decreasing diameter or cervical in shape along the gas flow path as depicted in fig2 within the vessel 2 there is placed adsorbent material effective to selectively adsorb the most easily sorbed contaminant in the preferred embodiment the most easily sorbed contaminant in feed air is water and the adsorbent material is preferably alumina based spheres preferably a supportive alumina adsorbent section.