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

Abstract

The binary diffusion coefficients of 2-ethyltoluene, 3-ethyltoluene, and 4-ethyltoluene in supercritical carbon dioxide were determined in a pressure range of (15.0 to 35.0) MPa at temperatures of (313, 323, and 333) K by means of the Taylor-Aris dispersion technique. The influence of pressure, temperature, density, and viscosity on the binary diffusion coefficients was examined, and some general trends were established. The experimental results were compared with the values estimated by several semiempirical equations based on the Stokes-Einstein formula and on the Rough-Hard-Sphere model.

Diffusion coefficients of phenylbutazone in supercritical CO2 and in ethanol

“…Although the Eq. (3) is in excellent agreement with the D 12 data in the higher pressure region, which also can be seen in literature [24,[26][27][28][29], there is a significant deviation from the experimental data in the lower pressure region at each constant temperature. method in this study.…”

Measurement and correlation of binary diffusion coefficients of lithium acetylacetonate in supercritical carbon dioxide and in liquid ethanol

“…The D 12 values simply increased with decreasing P and increasing T. The greater P sensitivity of D 12 at lower P indicates that the fluid or viscosity Á is remarkable factor, because these properties change rapidly with P in this region. Similar D 12 behavior was found in sc carbon dioxide in the literature for acetone [8,9,18], alkane [18], benzene [18], caffeine [19], ␤-carotene [8,20], cobalt(III) acetylacetonate [21], 1,2-diethylbenzene [22], 1,4-diethylbenzene [22], diethyl ether [23], diisopropyl ether [23], dimethylnaphthalene [24], 2-ethyltoluene [25], 3-ethyltoluene [25], 4-ethyltoluene [25], hexachlorobenzene [26], naphthalene [19,24,27,28,26], phenol [8,9], palladium(II) acetylacetonate [21], phenanthrene [26], phenylacetic acid [28], phenylacetylene [22], phenylbutazone [10], tetrahydrofuran [23], triarachidonin [29], trinervonin [29], trierucin [29], ␣-tocopherol [8,20], ubiquinone (UQ-10) [20,30], vanillin [28], vitamin K 3 [20,31] and 5-tert-butyl-m-xylene [22]. As shown in …”

Molecular Dynamics Simulation of Diffusion and Structure of Some n-Alkanes in near Critical and Supercritical Carbon Dioxide at Infinite Dilution

“…The diffusion coefficient at high pressures is very important for estimating the separation rate and designing separation processes. However, it is very difficult and expensive to determine diffusion data experimentally because of the rigorous experimental conditions required. − The Taylor dispersion method was applied to determinate diffusion coefficients of various organic compounds in supercritical carbon dioxide (scCO 2 ) and which were correlated with molecular parameters and viscosity of fluids by several empirical equations. − At present, computer simulation has already become one of the most important methods for obtaining diffusion coefficients of fluids. − Moreover, such simulations can provide detailed and valuable characteristic pictures of molecular structure at the atomic level. − …”