The pressure drop characteristics, dynamic column breakthrough, and pulsed-pressure-swing-adsorption (PPSA) experiments in an adsorption column packed with very fine 5A zeolite particles of mixed size in the range 63-75 mu m are presented. A multipurpose experimental setup was designed and constructed to perform these experiments. The pressure drop and axial dispersion were very high in the adsorption column. Darcy's equation and the correlation by Langer et al. were recalibrated to account for the increased pressure drop and enhanced axial dispersion, respectively. With these recalibrated constituent models, the numerical process model, solved using COMSOL Multiphysics software, was able to correctly capture the measured experimental breakthrough and PPSA performance results. The principal conclusion from this study is that the high axial dispersion and pressure drop in a column packed with very fine 5A zeolite particles are due to the surface roughness and clustering of the particles and channeling in the column, which are detrimental to the performance of the PPSA process. Therefore, the maximum oxygen product purity obtained in a simple two-step PPSA process was limited to <40%. The challenges of designing a small and lightweight oxygen concentrator to deliver >= 90% O-2 concentration for Chronic Obstructive Pulmonary Disease patients are also identified.