IWNET12
IWNET12
Liquid-vapour interface transfer coe cients of a two-component mix-
ture
J.-M. Simon1, I. Inzoli2, S. Kjelstrup3, D. Bedeaux3
1 Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, Dijon,
France
2 EXPEC Advanced Research Center, Saudi Aramco, Dhahram, Saudi Arabia
3 Department of Chemistry, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
Abstract
Exchanges of mass and energy between dierent bulk phases occur through interfaces and surfaces. The mass
and energy transfers could be well described in bulk phases using the non-equilibrium thermodynamics; its
extension to interfaces was systematically investigated the last ten years using molecular dynamics simulation [1].
Evaporation / condensation processes are endothermic / exothermic phenomena, as a consequence the surface
exhibits large couplings between heat and mass transfer, stronger than in the adjacent bulk phases. This eect
strongly in uences the dynamics of evaporation / condensation. In the presentation after a short overview of
the entropy production expressions and the transport equations applied to surfaces, molecular dynamics results
of a liquid-vapor system of a two-component mixture composed of Lennard-Jones atoms submitted to external
heat and mass uxes [2] will be shown. Comparing with equilibrium simulations, it was veri ed that the local
equilibrium hypothesis was valid for the whole surface, which is an important hypothesis of non-equilibrium
thermodynamics. Based on the transport equations, the transfer coe cients, i.e. the resistivities to heat and
mass transfer and their coupling were then computed using direct method and the integral relations. Like for
the one component systems, the results show the large thermal diusion eects that cannot be neglected in
order to model the dynamics of evaporation / condensation, adsorption / desorption processes.
References
[1] Signe Kjelstrup and Dick Bedeaux "Non-equilibrium thermodynamics of heterogeneous systems", Series on
Advances in Statistical Mechanics, Vol. 16, 2008 World Scienti c, Singapore.
[2] I. Inzoli, S. Kjelstrup, D. Bedeaux, J.-M. Simon, Chemical Engineering Science vol. 66, 4533 (2011)
E-mail: jmsimon@u-bourgogne.fr