Vapor−Liquid Equilibria for the Carbon Dioxide + Pentane and Carbon Dioxide + Toluene Systems

Abstract

Vapor−liquid equilibrium data have been measured for the systems carbon dioxide + pentane at (310.15, 333.15, and 363.15) K and carbon dioxide + toluene at 323.15 K and 333.15 K. The experimental data have been correlated by the Peng−Robinson equation of state with one interaction parameter. In addition, the group pair parameters relating to CH2 + CO2 and ArCH + CO2 in the PRASOG group contribution model are determined.

Liquid‐liquid phase split in ionic liquid + toluene mixtures induced by CO2

“…The solubility of CO 2 was measured in the liquid phase of toluene at 298, 313, and 333 K in order to compare with literature data. We observed an average error of 1% (a maximum of ±0.02 mole fraction) when comparing our results with values shown in literature …”

“…For example, for duplicate or triplicate measurements at pressures that differ by less than 0.12 MPa we estimated the uncertainty in the CO 2 solubility as the standard deviation in the mole fraction for those replicates. After comparing repeatability between our data and reproducibility with literature values of the binary system CO 2 + toluene and CO 2 + [hmim][Tf 2 N], we estimate the uncertainty to be ±0.01 mole fraction of CO 2 for pressures over 3 MPa and ±0.02 mole fraction for pressures below 3 MPa for binary and ternary systems. This is true for both binary (IL + CO 2 and toluene + CO 2 ) and ternary (IL + toluene + CO 2 ) systems.…”

“…Calculations are also performed with the Span–Wagner equation, assuming that the gas phase is pure CO 2 . In the literature, compositions of toluene in the gas phase are no larger than 0.008 mole fraction at 313.15 K and 0.021 mole fraction at 333.15 K within the range of pressures studied. Thus, the density should not be modified significantly with the small amount of toluene dissolved in the CO 2 gas phase.…”

Cromatografia unificada

“…Para facilitar a escolha de uma mistura de fases móveis que seja ideal para um determinado sistema, sem a necessidade de testar experimentalmente uma enorme variedade de solventes e suas proporções, podem ser empregados cálculos teóricos utilizando estudos de propriedades físico-químicas já realizados para uma variedade de misturas, mesmo que não tenham sido levadas em considerações as propriedades cromatográficas das mesmas, como estudo de equilí-brios entre fases, viscosidade e densidade [31][32][33][34] , entre outros. Nos sistemas unificados, desenvolvidos até então, foram empregados hélio para GC e CO 2 para SFC, independentemente [26][27][28][29][30] , metanol e éter dietílico como gás e líquido 24 , ou éter etílico como gás e fluido supercrítico 25 .…”

Phase Behavior of the System (Carbon Dioxide + n-Heptane + Methylbenzene): A Comparison between Experimental Data and SAFT-γ-Mie Predictions

“…The system xCO2 + (1 -x)C7H8 has been studied recently by Lay and coworkers 13,14 at pressures up to 7.5 MPa, temperatures up to 313 K, and composition over the range x = (0.215 to 0.955) using a pVT apparatus with a variable volume cell. Tochigi et al 15 also studied the system at pressures up to 6.0 MPa, temperatures up to 333 K and composition over the range x = (0.080 to 0.889) using a static-type apparatus composed of an equilibrium cell, sampling and analysis system. Wu et al 16 extended the conditions investigated up to p = 16.6 MPa and T = 572 K, for x = (0.01 to 0.78), by using a dynamic-synthetic method based on a fiber optic reflectometer; this is the widest range studied for this mixture.…”