Grand canonical Monte Carlo study of Lennard-Jones mixtures in slit pores. Part 3.—Mixtures of two molecular fluids: ethane and propane

Abstract

Mixtures of ethane and propane in a slit micropore at ambient temperatures have been simulated in the grand ensemble. Ethane was modelled as two Lennard-Jones sites and propane as three Lennard-Jones sites. A new type of selectivity–pressure profile, outside the Tan–Gubbins classification, has been noted. The mixed adsorption of the two gases was found to be thermodynamically ideal. Molecular shape and pore size were found to play an important role in determining the extent of adsorptive separation. Much of the observed behaviour is shown to be entropy driven.