Application of the corresponding states principle to the diffusion in CO₂

Abstract

in Wiley InterScience (www.interscience.wiley.com).Binary diffusion coefficients at infinite dilution in supercritical carbon dioxide, D AB , have been measured for the four monohalogenated benzenes (fluorobenzene, chlorobenzene, bromobenzene, and iodobenzene) with the Taylor-Aris technique in a chromatographic apparatus as a function of temperature and pressure. The ranges covered for these two variables were 313-333 K and 15.0-35.0 MPa, respectively. As the four solutes are similar molecules, the corresponding states principle (CSP) has been tested, together with the results of several predictive equations.

Binary Diffusion Coefficients of 2-Ethyltoluene, 3-Ethyltoluene, and 4-Ethyltoluene in Supercritical Carbon Dioxide

“…Knowledge of properties like solubility or diffusion coefficient in supercritical carbon dioxide is essential for evaluating the feasibility of supercritical separation processes and for establishing optimum conditions of operation. The data available on diffusivity are limited, but recent research has increased the database for binary diffusion coefficients and has made it possible to explore their influence on solute diffusivities. − Furthermore, good predictive and correlation methods for diffusion coefficients in supercritical carbon dioxide are desirable.…”

Correlation of Infinite-Dilution Diffusion Coefficients in Supercritical Fluids

“… a Data source: ref . b V B was calculated by the Lee−Kesler equation of state (ref ). c Deviation (%) = 100 ( D AB,cal − D AB,exp )/ D AB,exp . …”

“…solvent (B): carbon dioxide (114 binary systems, 1575 data points, T rB ) 1.00-1.31, F rB ) 0.42-2.34) solutes (A) (M A ) 58.08-885.40 g/mol, F A,298K ) 0.63-2.04): acetone, 13-15 acridine, 16 allylbenzene, 9 aniline, 17 benzaldehyde, 15 benzene, 13-15,18-24 benzoic acid, 5,16 benzyl acetate, 25 benzyl ether, 15 benzylacetone, 26 2-bromoanisole, 9 bromobenzene, 2,6 2-butanone, 15 (C4:0; C8:0; C10:0; C14:0; C16:0; C18:0; C22:0; C22:6 a ) ethyl ester, 27 (C14:1; C18:2; C20:1; C20:5; C22:1; C22:6 a ) methyl ester, 20,27,28 caffeine, 29,30 chlorobenzene, 2,6 chloroform, 15 chrysene, 13 cis-jasmone, 20 cycloheptanone, 31 cyclononanone, 31 cyclopentanone, 31 dibenzyl ether, 25 1,2-dichlorobenzene, 32 dichloromethane, 15 1,2-diethylbenzene, 33 1,4-diethylbenzene, 33 diethyl ether, 15,34 diisopropyl ether, 34 2,3-dimethylaniline, 35 2,6-dimethylaniline, 35 1,4-dioxane, 15 1,3-divinylbenzene, 9 ethyl acetate, 15,29 ethyl benzoate, 26 ethylbenzene, 15,19 2-ethyltoluene, 36 3-ethyltoluene, 36 4-ethyltoluene, 36 eugenol, 26 2-fluoroanisole, 9 fluorobenzene, 6 glycerol trioleate, 5 3-heptanone, 31 hexachlorobenzene, 37 indole, 20 iodobenzene, 2,6 isopropylbenzene, 15,19 limonene, 15,20 m-cresol, 22 m-xylene, 2,15 mesitylene, 2,13,15,17,18 2-methylanisole, 35 4-methylanisole, 35 n-butylbenzene, 7 n-decane, 14 n-dodecane, 14 n-heptane, 14 n-hexane, 14 n-nonane, 14 n-octane, 14 n-pentane, 14 n-pentylbenzene, 7 n-propylbenzene, 15,18,19 n-tetradecane, 14 n-undecane, 14 naphthalene, 5,13,20,24,30,37-41 2-nitroanisole, 32 nitrobenzene, 2 3-nitrotoluene, 35 5-nonanone, 31 o-xylene, 2,15 1-octene, 15 oleic acid, 5 p-xylene, 2,15 3-pentanone, 31 phenanthrene, 13,16,37 phenol...…”

“…[1][2][3][4][5] In general, such experimental apparatus is relatively expensive and the experimental procedure is always time-consuming and difficult to measure with high precision. Therefore, more than 20 famous equations have been proposed to estimate the infinite-dilution diffusion coefficients in supercritical fluids, [6][7][8][9] which can be roughly classified into two groups: Stokes-Einstein type and rough-hard-sphere type. Among them, the He-Yu equation 10 is highly recommended for its accuracy, generality, convenience, and simplicity.…”

“…During the past three decades, mainly through the Taylor−Aris chromatographic dispersion technique, thousands of data points of infinite-dilution diffusion coefficients in supercritical fluids have been measured and published. − In general, such experimental apparatus is relatively expensive and the experimental procedure is always time-consuming and difficult to measure with high precision. Therefore, more than 20 famous equations have been proposed to estimate the infinite-dilution diffusion coefficients in supercritical fluids, − which can be roughly classified into two groups: Stokes−Einstein type and rough-hard-sphere type. Among them, the He−Yu equation is highly recommended for its accuracy, generality, convenience, and simplicity .…”