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Generalization of gas‐liquid partition chromatography to study high pressure vapor‐liquid equilibria of multicomponent systems
Author(s) -
Koonce K. Terry,
Deans H. A.,
Kobayashi Riki
Publication year - 1965
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690110216
Subject(s) - elution , chemistry , propane , chromatography , ternary operation , methane , gas chromatography , volume (thermodynamics) , component (thermodynamics) , phase (matter) , thermodynamics , analytical chemistry (journal) , organic chemistry , physics , computer science , programming language
The use of chromatographic retention volume data to obtain vapor‐liquid equilibrium coefficients has been extended to a ternary system with all components present at finite concentrations in the liquid phase and essentially a light binary gas comprising the vapor phase. The data are obtained by observing the retention time of the solute of interest when that solute is eluted by a flowing gas stream through a column packed with an inert porous firebrick on which is impregnated a fixed, relatively nonvolatile liquid. The retention times are used to compute retention volumes which may be related to the K values of the solute. A previous mathematical description of the elution process is modified to include the case of an N component elution gas, all constituents of which are soluble in the fixed liquid phase. A general solution is derived for the multicomponent elution gas from which K values for each component may be calculated if retention volume data are taken for each, provided molecules of the solute samples used are distinguishable from others of the same species present in the eloution gas. For the case of indistinguishable sample molecules, the rate theory development of Stalkup and Deans is verified for a binary elution gas. Sufficient retention data were taken to completely define the concentration dependence of the K value for propane in the system methane‐propane‐ n ‐decane at −20°, 0°, 40°, and 70°F. from 20 to 1,000 lb/sq.in.abs. Six methane‐propane binary mixtures were used as elution gases, consisting of 2.08, 4.31, 6.90, 9.44, 13.09, 16.27 mole % propane. Retention data were also taken for methane under the same conditions. Distinguishability of sample molecules was achieved by using radioactive solute samples tagged with carbon‐14. Propane retention data were also obtained for the system methane‐propane‐ n ‐heptane at −20° and −40°F. from 100 to 1,000 lb./sq.in.abs. for propane at infinite dilution and for binary elution gases composed of 2.08 mole % propane at −40°F. and 4.31 mole % propane at −20°F. All K values determined chromatographically were either compared directly with published static equilibrium values or tested for consistency with such values and found to be in substantial agreement.