Monte Carlo simulations of n-butane and n-octane adsorbed onto graphite and a molecular model of activated carbon

Abstract

In this work we report results of Monte Carlo simulations of n-butane and n-octane adsorbed onto graphite and a molecular model of activated carbon, with the aim to provide simplified models that will allow the study of these kind of systems with lower computational and time costs. A combination of Coarse Grain models (CG) and Monte Carlo simulations (MC) were used. Adsorbates were reduced from four atoms to one pseudoatom and the adsorbent carbons from two atoms to one pseudoatom. We compare the results between atomistic models results and CG models for n-alkanes (single and mixture) adsorption on carbon surfaces, and we took into account the isosteric heat too. The simulation results showed an excellent agreement with the atomistic model for n-alkanes adsorption on graphite, using the CG model. However, for the activated carbons studied there is no longer such a good agreement between atomistic models and coarse-grained models.