  The phenomena of diffusion in multicomponent (more than two components)
mixtures are very universal in both science and engineering, and from
mathematical point of view, they are usually described by the Maxwell-Stefan
(MS) based continuum equations. In this paper, we propose a
multiple-relaxation-time lattice Boltzmann (LB) model for the mass diffusion in
multicomponent mixtures, and also perform a Chapman-Enskog analysis to show
that the MS based continuum equations can be correctly recovered from the
developed LB model. In addition, considering the fact that the MS based
continuum equations are just a diffusion type of partial differential
equations, we can also adopt much simpler lattice structures to reduce the
computational cost of present LB model. We then conduct some simulations to
test this model, and find that the results are in good agreement with some
available works. Besides, the reverse diffusion, osmotic diffusion and
diffusion barrier phenomena are also captured. Finally, compared to the kinetic
theory based LB models for multicomponent gas diffusion, the present model does
not include any complicated interpolations, and its collision process can be
still implemented locally. Therefore, the advantages of single-component LB
method can also be preserved in present LB model.
