Evaluation of experimental methods for the study of liquid-phase adsorption of alkane/alkene mixtures on Y zeolites

Liquid phase adsorption of alkane/alkene mixtures on NaY was studied using different methods. It was shown that the presence of traces of water in the feed, has a tremendous influence on subsequent measurements during continuous flow through experiments. The hydrophilic character of the adsorbent combined with the inevitable presence of water inside the mobile phase made the application of the pulse chromatographic technique impossible. The influence of water became neglectable in an optimized batch technique allowing to determine binary adsorption isotherms of alkane/alkene mixtures in the low alkene concentration range (0-15wt%). 1-octene was shown to adsorb more selective from decane and dodecane than from its mixture with hexane or heptane on NaY. This unexpected selectivity effect was attributed to molecular packing in the supercages of NaY.