Pressure swing adsorption(PSA) is a well established process for separation or purification of gas mixtures in the chemical industries. Nowdays, the importance of this process increases because it has been widely used as an alternative for cryogenic p...
Pressure swing adsorption(PSA) is a well established process for separation or purification of gas mixtures in the chemical industries. Nowdays, the importance of this process increases because it has been widely used as an alternative for cryogenic processes for the on-site generation of nitrogen, oxygen and hydrogen. As further process improvements are made, PSA will more favorably at higher production rates.
Zeolites, which preferentially adsorb nitrogen, are used for the production of oxygen from air, while for the production of nitrogen, carbon molecular sieves(CMS) are the preferred adsorbents.
In this work, it was investigated adsorption equilibria of pure oxygen, nitrogen and argon in carbonaceous materials such as an activated carbon(AC), single-walled nanotubes(SWNTs) and multi-walled nanotubes(MWNTs).
The microporous structure of AC was a slit-shaped pore while SWNTs and MWNTs were cylindrical structure. This different pore structure and pore size distribution may be led to difference in isotherm equilibrium of oxygen, nitrogen and argon. The adsorption capacity of oxygen and nitrogen was in the order AC> SWNTs> MWNTs, while the selectivity was SWNTs> MWNTs> AC.