| Abstract
| - The liquid-phase adsorption of C5−C24 linear alkanes in zeolite 5A at room temperature was studied usingthe configurational bias Monte Carlo molecular modeling technique and the batch experimental method. Upto C16, a highly discontinuous variation of the saturation capacity with the carbon number occurred. Whereasthe shortest chains remain as a whole within the cage, longer chains are distributed in a more bent configurationover adjacent cages or even adopt highly coiled configurations within one cage. For alkanes greater than C16,a sharp, unexpected drop in adsorption capacity with a minimum at C18−C19 was observed experimentally.The almost complete exclusion of these alkanes was not observed in the molecular simulation under equilibriumconditions and is explained by an extremely slow diffusion of C18−C19 because of “cage nestling”, i.e., animperturbable adsorption of tightly fitting highly coiled n-alkanes in the first supercage they enter. Thecompetitive adsorption and counterdiffusion of alkane mixtures is strongly affected by the differences inadsorption mechanism for alkanes of different chain length.
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