PSA Nitrogen generation plant will work on the concept of absorbing Oxygen from compressed air(CMS). this plant consists of two adsorbers filled with carbon molecular sieves. Compressed and purified air is passed through the absorbers in this process. Mainly oxygen is absorbed on the carbon molecular sieves as it has preferential properties for adsorption of moisture first and nitrogen enriched gas is leaving the absorber. The oxygen concentration can be reduced to almost all required levels. During adsorption in one adsorber, the second adsorber is totally regenerated just by depressurization to ambient pressure. The oxygen enriched off gas is vented. After about one minute adsorption in one adsorber, the process controller is switching over to the second adsorber to produce nitrogen on a continuous basis.