resumo
In this work, the permeation of pure adsorbable molecules and their mixtures through microporous materials has been studied. New expressions for the Maxwell-Stefan thermodynamic factors were derived for mono and multicomponent Nitta, Langmuir-Freundlich, and Toth isotherms, being tested with equilibrium and permeation data from the literature. In the whole, the results achieved evidence the new models are able to represent data for pure components and predict binary permeation. In the most interesting case of binary mixtures, the validation procedure adopted was very stringent: (i) multicomponent isotherms were predicted from pure gas data; (ii) diffusion parameters of pure components were fitted to single permeation data; (iii) the Maxwell-Stefan crossed diffusivities were estimated by the Vignes relation; finally, and (iv) the new equations were used with these parameters to predict binary permeation fluxes. (C) 2010 Elsevier B.V. All rights reserved.
palavras-chave
MAXWELL-STEFAN EQUATIONS; MOLECULAR SIMULATIONS; SILICALITE-1 MEMBRANE; LIGHT ALKANES; ADSORPTION EQUILIBRIA; SEPARATION PROCESSES; SURFACE-DIFFUSION; MIXTURES; DEPENDENCE; COMPONENT
categoria
Engineering; Polymer Science
autores
Lito, PF; Santiago, AS; Cardoso, SP; Figueiredo, BR; Silva, CM
nossos autores
agradecimentos
Patricia F. Lito and Ana S. Santiago wish to thank grants provided by Fundacao para a Ciencia e Tecnologia (Portugal) (SFRH/BD/25580/2005 and SFRH/BPD/48258/2008). This work was supported by research project PTDC/EQU-EQU/100476/2008 of FCT.