Prediction of effective diffusivity tensors for bulk diffusion with chemical reactions in porous media

• Autor(a) principal: Silva,E. A. Borges da
• Data de Publicação: 2007
• Outros Autores: Souza,D. P., Souza,A. A. Ulson de, Souza,S. M. A. Guelli U. de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Chemical Engineering
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322007000100005
• topic: Effective diffusivity tensor; Method of volume averaging; Closure problems; Porous media

In this paper, the volume averaging transport equations of two reactive processes in porous media are presented. The porous media are characterized by different length scales and the information describing the mass transfer mechanisms is transferred hierarchically between scales by applying the volume averaging method. This development provides the theoretical definition of effective transport coefficients, which can be predicted through solution of the closure problems. The theoretical calculation of effective diffusion tensors of the species in the particle pores is presented. Two closure problems are deduced through mathematical formulation of two different scales: microporous (process 1) and macroporous (process 2). In order to solve these closure problems, the volume finite method is used as the numerical methodology. Good agreement is verified between the numerical solutions obtained in this study and the data found in the literature for the closure problems considered.