- 2:40 PM

Molecular Modeling Study of Adsorption and Diffusion of Mixed Gases in Cubtc Metal Organic Framework

Karl Johnson1, Jinchen Liu1, Seda Keskin2, and David S. Sholl2. (1) University of Pittsburgh, 1249 Benedum Hall, Department of Chemical Engineering, Pittsburgh, PA 15261, (2) Carnegie Mellon University, Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213

We use atomically detailed simulations and continuum theory to study the adsorption and diffusion of mixed gases in the metal organic framework known as CuBTC. We have computed pure fluid and mixture isotherms for CH4, CO2, and H2 in CuBTC from grand canonical Monte Carlo simulations. We compare our mixture isotherms with predictions from the ideal adsorbed solution theory. We have used equilibrium molecular dynamics to compute self and transport diffusivities for the pure fluids. We have predicted the mixed gas diffusion coefficients from SSK theory. We have compared the SSK theory predictions with mixed gas diffusivities computed from equilibrium molecular dynamics. We assess the accuracy of the SSK theory and discuss prediction of macroscopic permeance and selectivity based on predictions from simulations and SSK theory.