title: Transient separation of multicomponent liquid mixtures in thermogravitational columns.
abstract: Transient separation of the individual components in a multicomponent liquid mixture in a thermogravitational column can be used to determine the thermal and molecular diffusion coefficients. Two models of the transient behavior are developed. First, a classical model where density only depends on temperature. Second, a general model where the compositional effect on density is also taken into account. Diffusion coefficients can be determined by fitting experimental data to either model. The procedure is demonstrated for a ternary liquid mixture. The results reveal that the classical model is very unreliable even though composition variation only contributes to the total buoyancy by one-third. Diffusion coefficients can be obtained reliably from the general model provided the experimental noise does not exceed +/-1% of steady-state separation. This level of accuracy in composition measurements is achievable.
authors.affiliation: Department of Chemical Engineering, Room 103, Mason Lab., Yale University, New Haven, Connecticut 06520-8286, USA. kjetil.haugen@yale.edu
authors.forename: Kjetil B
authors.initials: KB
authors.lastname: Haugen
authors.forename: Abbas
authors.initials: A
authors.lastname: Firoozabadi