Adsorption of Acetone / Heptane Gaseous Mixtures on Zeolite Co-Adsorption Equilibria and Selectivities

Abstract

In the present study, co-adsorption of gaseous n-heptane and acetone is studied. The adsorbent is a commercial hydrophobic zeolite. Breakthrough curves and isotherms are measured for three different acetone/heptane mixture ratios and for pure components. Zeolites showed a greater adsorption capacity for acetone alone than for heptane alone. For the mixtures, the majority component was the most adsorbed. Zeolites have a good selectivity for acetone even though acetone is more volatile than heptane. Specific adsorption sites are reserved for acetone adsorption and are not accessible to heptane. The polarity of a component leads to electrostatic interactions with cation exchange. On non-specific adsorption sites, acetone can be displaced by heptane, which is less volatile. Moreover, experiments show that selectivity depends on the ratio of the mixture. For co-adsorption of a mixture of polar and non-polar components, selectivity depends on relative polarity, mixture ratio, and boiling point.