Comparative study of pure component adsorption of linear alkanes in zeolites MFI, BEA and MOR

Abstract

Grand canonical Monte Carlo (GCMC) simulations and configurational-bias Monte Carlo simulations (CBMC) have been performed to compute and compare the pure component adsorption isotherms of C1–C7 linear alkanes in MFI, BEA, and MOR zeolites at 300 K. It is demonstrated that generally, the surfaces of the three zeolites available for adsorption are not energetically homogeneous; adsorption of the alkanes in the three zeolites can be divided into two steps, in the first step of which molecules are adsorbed in the strong sites and on the later of which on the weak sites; all isotherms obtained can be well described by the dual-site Langmuir equation, though the saturation loadings and the adsorption strengths are different for the three different topologic zeolites. A quantitative analysis of the isotherms shows that the Henry’s law constants in the three zeolites obey a similar linear relation to the number of carbon atoms of the alkanes.