Molecular Dynamics Simulation of Transport and Separation of Carbon Dioxide–Alkane Mixtures in a Nanoporous Membrane Under Sub- and Supercritical Conditions

Abstract

Extensive nonequilibrium molecular dynamics simulations were carried out to study the transport and separation of binary mixtures of $$\hbox {CO}_2$$ and n-alkane chains in a molecular pore network model of nanoporous carbon molecular-sieve membrane. Separation of both sub- and supercritical mixtures was studied. The membrane was generated atomistically by the Voronoi tessellation of the space, using tens of thousands of atoms. The simulations indicate that there is an optimal pressure drop for separation of mixtures of $$\hbox {CO}_2$$ and n-alkanes, when the mixtures enter the membrane under supercritical conditions. In addition, separation of $$\hbox {CO}_2$$ from n-alkanes becomes increasingly more efficient as the size of the alkane increases.