(458b) N2 Selective Cation Exchanged Clinoptilolite - Adsorption Separation of N2 from CH4 Containing Mixtures  | AIChE

(458b) N2 Selective Cation Exchanged Clinoptilolite - Adsorption Separation of N2 from CH4 Containing Mixtures 

Authors 

Kennedy, D. - Presenter, University of Ottawa
Tezel, F. H., University of Ottawa
Mujcin, M., University of Ottawa
In this study, a new modified N2 selective adsorbent material was developed for the application N2 removal from unconventional natural gas and biogas upgrading processes where inert nitrogen contamination is a concern. Adsorption based separations have the potential to achieve a more economically efficient separation of N2 from hydrocarbon mixtures containing CH4 than current separation processes such as cryogenic distillation. Most commercially available adsorbents are only moderately selective for CH4 over N2; however, inverse selectivity is desired for this separation for applications such as pressure swing adsorption in order to maintain the CH4 gas in the higher pressure raffinate stream. Currently, the only N2 selective adsorbent that has shown commercial success for this application is titanosilicate ETS-4.

The potential of cation exchanged clinoptilolite adsorbents were studied for the selective separation of N2 from CH4 containing gas mixtures. Single component equilibrium adsorption isotherms and uptake measurements of CH4 and N2 confirm the promising N2 selective properties for both cation exchanged powders and pellets. Adsorption breakthrough curve experiments were used to show the effects of column dynamics and competitive adsorption of CH4 and N2 containing mixtures on the new materials.