The annular packed bed adsorber is a promising development, because it offers a greatly reduced resistance to flow. Experimental and modelling work on the bed dynamics are described herein. A one-dimensional model of adsorption has been formulated. Thereafter, tests with different numbers of collocation points agree to the fourth significant figure. Similarly, our predictions can agree very well with Rosen's predictions for planar systems. (For these comparisons, gas residence times were identical, and axial dispersions were ignored). The characteristics of zeolite 4A - pore diffusivities and Volmer isotherms - have been measured gravimetrically. They have been fed to a one-dimensional, dynamic, numerical model of the bed. Predictions were compared against recorded histories of concentration versus time at three sample points within the bed. For outward flow, the agreement between prediction and measurement is respectable at the bed outlet. For inward flow, experimental results provide evidence of flow maldistribution. (This is supported by previously reported work). Thus, any comparison with a one-dimensional model is inappropriate. The influences of co-adsorption, heat of adsorption and maldistribution are worthy of future investigation.