IWNET12
IWNET12
On the (im-) possibility of cold to warm distillation
Henning Struchtrup1, Signe Kjelstrup2, Dick Bedeaux2
1 University of Victoria, Canada
2 Department of Chemistry, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
Abstract
Irreversible thermodynamics provides interface conditions that yield temperature and chemical potential jumps
at phase boundaries. The interfacial jumps allow unexpected transport phenomena, such as the inverted tem-
perature prole [Pao, Phys. Fluids 14, 306-312 (1971)] and mass transfer from a cold to a warm liquid driven
by a temperature dierence across the vapor phase [Mills & Phillips, Chem. Phys. Lett. 372, 615619 (2002)].
Careful evaluation of the thermodynamic laws has shown [Bedeaux, Hermans & Ytrehus, Physica A 169, 263-
280, 1990] that the inverted temperature prole will be observed for processes with a large heat of vaporization.
We show that cold to warm mass transfer through the vapor from a cold to a warm liquid is only possible when
the heat of evaporation is suciently small, as long as the vapor layer thickness is relatively small. Investiga-
tion of the overall experimental apparatus and the non-equilibrium interface conditions allows to estimate the
maximum vapor layer thickness that would permit this particular transport mode.
E-mail: struchtr@uvic.ca

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