A rotary adsorbent dryer is provided which includes a stationary outer housing having spaced stationary end walls, and a rotor mounted for rotation within the outer housing. A plurality of compressed gas passages pass through the end walls to provide compressed gas flow to or from a respective substantially open end of the rotor. A drive arrangement is provided which is cooperable with an outer circumferential region of the rotor so that it is not necessary to provide a drive shaft which extends axially through desiccant material within the rotor.