Método de caracterização adaptativa aplicado à transferência de massa em misturas contínuas com o modelo de difusão de Maxwell-Stefan

Abstract

The adaptive pseudo-component characterization method for continuous mixtures was extended to mass transfer problems using the Maxwell-Stefan diffusion model. Being based on the direct quadrature method of moments (DQMoM), it uses a quadrature rule to discretize the molar fraction distribution of the continuous mixture. The solution method was applied to two one-dimensional mass transfer problems: the transient diffusion in a Loschmidt tube and the steady-state diffusion in a thin film. In the latter, it was showed that the DQMoM equations reduce to an equivalent problem with a fixed characterization and the solution methods for linearized theory problems can be employed. For these two problems, the proposed method was validated using continuous molar fraction distributions as initial or boundary conditions. Results showed that the adaptive method accurately predicts mixture properties with one order of magnitude reduction in the number of the pseudo-components when compared to the discrete component model.