N2-PSA is a nitrogen gas generator with the specially designed adsorbent. This adsorbent is called Carbon Molecular Sieves (CMS) having a micro pore in its surface and adsorb O2, CO2 and H2O molecular into such hall selectively under a certain pressure. After adsorption process, adsorbent is regenerated by depressurizing. N2-PSA can produce the nitrogen gas continuously by repeating above adsorption and regeneration. For your reference PSA stands for Pressure Swing Adsorption