A combinatorial dynamic Monte Carlo approach to finding a suitable zeolite membrane structure for CO2/N2 separation

Dynamic Monte Carlo (DMC) simulations have been performed to estimate the perm-selectivity of binary mixtures (CO2/N2) in zeolite-like porous membranes. Various hypothesized porous structures, including a previously reported zeolite structure, were used to calculate the separation factor and permeability of CO2/N2. The rate coefficient for hopping between the adsorption sites used in the DMC calculation was estimated based on an empirical atomic force field. The membranes that have the structure of both a seven-membered ring (7MR) (0.34 nm) pore diameter and larger size of adsorption site with high dimensionality in pore architecture were shown to have a high separation factor for CO2. This simulation technique is proposed as a new methodology to search for the optimal structure of porous membranes for a specific given separation system. The advantage of this strategy of simulation is the reasonable calculation time compared with conventional techniques such as non-equilibrium molecular dynamics.