Equilibrium adsorption of a cyclopentane-benzene vapor mixture on active carbon

The data on adsorption of cyclopentane, benzene, and their mixture on activ e carbon were analyzed by the statistical thermodynamic model. A method to describe the state of a binary mixture in single micropores was offered. A substantial negative deviation from Raoult's law predicted by the concept o f an ideal adsorption solution is a consequence of a decrease in the excess ive Helmholtz energy brought about by progressive filling when values of th e excessive energy are positive over a wide range of adsorption. The excess ive values found for the entropy and internal energy of a mixture of molecu les in a single micropore are negative due to the heterogeneity of the adso rption field. The approach suggested adequately describes the experimental data and can be used for the determination of differential heats of adsorpt ion.