A MOLECULAR-DYNAMICS STUDY OF DIFFUSION OF METHANE IN PARTIALLY DEALUMINATED ZEOLITE-NA-A

The diffusion of methane in partially dealuminated zeolite Na A has be en studied by molecular dynamics using a vibrating framework model at different loadings and with different aluminium content. Methane molec ules were represented by Lennard-Jones particles. The computed diffusi on coefficients increase with increasing loading and decreasing alumin ium content, in agreement with experiment. The mechanism of the diffus ive process is discussed and a detailed analysis of the behaviour of m ethane molecules in partially dealuminated zeolite Na A is reported.