Abstract
We have used grand canonical Monte Carlo simulations to calculate the adsorption isotherms for H2, CH4, Xe and CF4 in Zn(tbip), a metal organic framework material having narrow 1D pores. Simulations show that Xe and CF4 form ordered solid structures when adsorbed in the pores. We have computed the self and transport diffusivities for H2, CH4, Xe and CF4 in Zn(tbip) using equilibrium molecular dynamics simulations. H2 has a diffusivity about one to two order of magnitude higher than CH4, indicating that transport selectivity for H2 over CH4 may be high. Xe and CF4 have very low diffusivities, in the order of 10− 9–10− 8 cm2/s. We have measured experimental adsorption isotherms for H2 at 77 and 298 K for pressures up to 60 bar in Zn(tbip). The H2 isotherms predicted from simulations are in reasonably good agreement with the experiments.
Acknowledgements
This work was performed in support of the National Energy Technology Laboratory's ongoing research in the area of carbon management under the RDS contract DE-AC26-04NT41817. This work was also supported by NETL under Grant Number DE-FC26-05NT42446 to SGS. We thank Dr Agustin F. Venero for many helpful discussions. Calculations were performed at the University of Pittsburgh Center for Simulation and Modeling.