Predicting diffusivities in dense fluid mixtures



Document title: Predicting diffusivities in dense fluid mixtures
Journal: Brazilian journal of chemical engineering
Database: PERIÓDICA
System number: 000308641
ISSN: 0104-6632
Authors: 1

Institutions: 1Universidade Federal do Rio de Janeiro, Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa de Engenharia, Rio de Janeiro. Brasil
Year:
Season: Sep
Volumen: 16
Number: 3
Pages: 213-227
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental, analítico
English abstract In this work the Enskog solution of the Boltzmann equation, as corrected by Speedy, together with the Weeks-Chandler-Andersen (WCA) perturbation theory of liquids is employed in correlating and predicting self-diffusivities of dense fluids. Afterwards this theory is used to estimate mutual diffusion coefficients of solutes at infinite dilution in sub and supercritical solvents. We have also investigated the behavior of Fick diffusion coefficients in the proximity of a binary vapor-liquid critical point since this subject is of great interest for extraction purposes. The approach presented here, which makes use of a density and temperature dependent hard-sphere diameter, is shown to be excellent for predicting diffusivities in dense pure fluids and fluid mixtures. The calculations involved highly nonideal mixtures as well as systems with high molecular asymmetry. The predicted diffusivities are in good agreement with the experimental data for the pure and binary systems. The methodology proposed here makes only use of pure component information and density of mixtures. The simple algebraic relations are proposed without any binary adjustable parameters and can be readily used for estimating diffusivities in multicomponent mixtures
Disciplines: Química
Keyword: Ingeniería química,
Mecánica estadística,
Coeficiente de difusión,
Mezclas
Keyword: Chemistry,
Chemical engineering,
Statistical mechanics,
Diffusion coefficient,
Mixtures
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