The solution-diffusion with imperfections model as a method to understand organic solvent nanofiltration of multicomponent systems

The solution-diffusion with imperfections model has been used together with diffusion models such as the Vrentas & Duda diffusion theory and the Wesselingh & Bollen multicomponent diffusion model as a tool to successfully describe the permeation behavior of mixtures of ketones and glycols through polydimethylsiloxane composite membranes in a cross-flow membrane cell for pressures varying from 10 to 40 bar. The model has shown the great importance of an accurate determination of the diffusion coefficients and the average concentration of permeants inside the membrane into the successful modeling of nanofiltration experiments.

► Mutual diffusivities of multicomponent systems are estimated.
► Reliable diffusivity values allow outstanding description of permeation.
► Reliable concentrations in the membrane allow outstanding description of permeation.
► Discussion of limitations in diffusion theories for multicomponent systems.