Microwave radiation's influence on sorption and competitive sorption in zeolites

The influence of microwave radiation on adsorption selectivity was studied using the adsorption and desorption of cyclohexane and methanol art high-si lica zeolites. The amount of microwave energy adsorbed depends on the speci fic system of adsorbent and adsorbate. The adsorbent a high-silica zeolite, is effectively "transparent" to microwave radiation, while the two adsorba tes reflect high (methanol) and low (cyclohexane) absorption of microwave e nergy. The measured system temperatures required for desorption by microwav e energy were lower than those required for conventional heating. Further, microwave radiation can change the sorption selectivity; the adsorbate with the greater microwave absorptivity is desorbed selectively. It is conclude d that the surface and adsorbed species can be heated selectively since the rate of microwave energy absorption can be greater than the rate of heat t ransfer from the surface.