(339a) Water and Organic Co-Transport in Carbon Molecular Sieve Membranes

Understanding molecular transport of mixtures in confined microporous spaces is an important research area for a variety of membrane separation processes. One important example is the transport of water and organic mixtures, especially in conditions of high guest loadings. Separation of water and small-molecule organic solvents is a challenge in industrial applications such as purification of produced water, solvent recovery from a water-organic mixture, and water removal from black liquor. Carbon molecular sieve (CMS) materials are a potential candidate for scalable and high-performance reverse osmosis membranes due to impressive chemical and thermal stabilities. The amorphous nature of the CMS microstructure results in significant difficulties in the use of computational modeling of molecular transport processes. Therefore, an experimental study of water and organic solvent transport in CMS membranes is pursued here. In this work, we investigated the sorption, diffusion, and permeation behavior of organic compounds and water in CMS. The comparison shows how the properties of penetrants such as hydrophilicity and molecular size of permeate affect the transport behavior in CMS. Basic transport and sorption parameters are utilized to estimate how water-organic mixtures will transport in a CMS membrane. Using the multicomponent sorption and transport frameworks based on pure component isotherms, flux equations of water and organic solvent mixture in CMS membranes are developed and compared with the experimental data.