The loading effect for gases, e.g., CH4 and CO2, was investigated . The amount of the gases affect the adsorption and selectivity. The gases are usually present as a mixture with different pressure. The interaction energies between CH4 molecules and ZIF-10 are almost constant regardless of the gas's loading due to the absence of interaction forces such as hydrogen bonds (HBs). On the other side, the interaction energies between CO2 and ZIF-10 decreased rapidly with the increase of the gas's loading . Gibbs ensemble Monte Carlo (GEMC) and molecular dynamics (MD) simulations were investigated for CO2 adsorption using ZIF-87 via diffusion .