Synthesis and modification of zeolite NaA adsorbents for separation of hydrogen and methane

To improve the adsorption capacity of zeolite A, two kinds of zeolite NaA with submicron and hierarchical structure were prepared. The XRD patterns indicated that both synthesized products were pure zeolite with LTA-type framework. The SEM images and laser particle size analysis showed that the particle size of submicron zeolite NaA was about 240 nm. The TEM and N-2 adsorption/desorption isotherms proved the existence of mesopores in the hierarchical zeolite NaA. The adsorption capacities of single component CH4 or H-2 on zcolite SrA adsorbents, obtained by Sr2+ ion-exchange of submicron and hierarchical zeolite NaA, and commercial zeolite 5A adsorbent were measured by the static volume method at 25 degrees C and pressures up to 1 MPa. The results show that both prepared zeolite SrA adsorbents have higher adsorption capacities of CH4 and ideal separation factors of CH4/H-2 than commercial zeolite 5A, and the submicron zeolite SrA has the largest adsorption capacity of CH4 and ideal separation factor of CH4/H-2. (c) 2009 Curtin University of Technology and John Wiley & Sons, Ltd.