Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
1999, Volume 2, Issue 3+4

Separation of Nitrogen from Air by Selective Adsorption on Carbon Molecular Sieves

Abstract

Carbon molecular sieves (CMS) are used on a wide scale for the separation of air into its components. CMS materials are kinetic adsorbents which separate N₂ frorn air by faster sorption of O₂ by the carbon. This paper presents the research results concerning the sorption kinetics of O₂ from air by CMS used a Pressure Swing Adsorption (PSA) single column (700 mm lenght, 50 mm i.d.). Romanian piteoal was used as carbon precursor for preparation of CMS. The molecular sieving properties of O₂ selective carbon molecular sieves CMS - HP (O₂), prepared under different conditions, were studied by measuring dynamic adsorption capacity for O₂. Also, N₂ production from air by CMS - HP(O₂) used PSA (two columns) simple and improved process, were studied. The gas flow velocity through the CMS bed determines the remaining O₂ concentration in the N₂ produced. By changing this velocity, the O₂ concentration can by adjusted between 0,03 ÷ 5,20% vol.