M. Delavar - Faculty of chemical Engineering, Babol University of Technology, Babol, Iran
N. Nabian - Faculty of chemical Engineering, Babol University of Technology, Babol, Iran
A Abbasi Godarzi - Department of Energy Engineering, Sharif University of Technology, Tehran, Iran

Equilibrium adsorption of pure oxygen and nitrogen were evaluated in two different carbonaceous adsorbents such as activated carbons (ACs) and carbonnanotubes (CNTs). To modify the surface characteristics of CNTs for adsorption operations, the chemical pretreatment operations were implemented.The equilibrium adsorption of oxygen and nitrogen on adsorbents were measured at pressure range of 0-25 bar in different temperatures. Due to the differentsurface structures of ACs and CNTs, the selectivity was different. A comparison between the separationfactors of CNTs and ACs showed that oxygen was adsorbed on CNTs better than nitrogen. However, the lowest separation factor obtained was 2.7 for oxygenand nitrogen adsorption on chemically pretreated CNTs revealing that the chemically pretreated CNTs improved the preferential adsorption of oxygen tonitrogen.