Adsorption of Methane on Several Zeolites by Monte Carlo Method

Grand Canonical Monte Carlo (GCMC) method is employed to simulate the adsorption of methane in several nanoporous zeolites. Adsorption isotherms over the temperature 177-398K and the pressure 0-12MPa are simulated. And their adsorption capacities of methane in these zeolites at different temperatures and pressures are also compared. The results show that: (1) the methane uptake is in the order of LTA>MOR>MFI at the same condition. The isosteric heat can support this conclusion: the value of isosteric heat in LTA is the largest, intermediate in MOR and the least in MFI. (2) The effects of the pore volume, channel size and the energetic interactions between zeolite and methane on adsorption amounts are considered. A large pore volume and a suitable channel size near to the kinetic diameter of a methane molecule are very important for improving the storage capacity of zeolites. Based on this, we conclude that LTA zeolite with a large pore volume and a suitable channel diameter exhibit a most efficient methane storage capacity than MOR and MFI zeolites.