Adsorption equilibria of hydrocarbon gaseous mixtures containing polar components

Adsorption equilibria were measured for binary systems of hydrocarbon gaseous mixtures containing polar components. Three different adsorbents were used: molecular sieve 13X, activated carbon G-2X and molecular sieving carbon MSC-5A. The experimental results were compared with results calculated according to two currently adopted prediction methods: the ideal adsorbed solution model and the two-dimensional fluid model. The adsorption equilibria of molecular sieve 13X were in good agreement with the predictions from both models. However, neither model was found to give a good fit with the adsorption equilibria obtained with the other adsorbents. It is shown that the adsorption equilibria of activated carbon G-2X can be well predicted by a modified two-dimensional fluid model which takes into account the distribution of the local molecular concentration. The experimental results obtained from molecular sieving carbon MSC-5A are considered to be accounted for by the nonuniformity of the adsorption energy.