Molecular simulations of methane adsorption in silicalite

Grand canonical ensemble Monte Carlo (GCMC) simulations of methane in the zeolite silicalite have been used to predict adsorption isotherms over a wide range of occupancies at several temperatures. The zeolite has been modeled using a detailed atomistic description, as have the methane molecules. Lennard-Jones parameters for the atomic interactions have been taken from the literature. Adsorption isotherms and heats of sorption have been predicted in good agreement with experiment. Structural features of the intracrystalline fluid have also been studied. In a complementary study, the test particle insertion method has been used to generate isotherms from molecular dynamics simulations. The results are in excellent agreement with those from GCMC.