Solubility of Carbon Dioxide in Two Pentaerythritol Ester Oils between (283 and 333) K

Abstract

In this work, the solubility of carbon dioxide, CO 2 , in pentaerythritol tetrapentanoate (PEC5) and in pentaerythritol tetra(2-ethylhexanoate) (PEBE8) has been performed from (283 to 333) K and pressures up to 7 MPa in a new high-pressure gas solubility apparatus. The results show that in the present analyzed range CO 2 is highly soluble in these oils and that the solubility expressed as CO 2 mole fraction is practically not dependent on the branching of the acid chain, whereas it increases slightly with the length of the PE acid chains in the present range of compositions. The gas solubility data were satisfactorily correlated with the Soave-Redlich-Kwong (SRK) equation of state (EOS) using the conventional quadratic mixing rule with two interaction parameters for each temperature.

Solubility measurements and correlation of carbon dioxide in pentaerythritol tetra-2-methylhexanoate. Comparison with other pentaerythritol esters

“…In the literature, only Fandiño et al [11] measured the solubility of CO 2 in pentaerythritol esters (PEC5 and PEBE8) and the comparison with our measurements for PEC5 at 283 K showed a good agreement. However, for the purposes of this discussion, we will consider only data produced at our laboratory.…”

Solubility of Carbon Dioxide in Pentaerythritol Tetrabutyrate (PEC4) and Comparison with Other Linear Chained Pentaerythritol Tetraalkyl Esters

“…However, small but systematic deviations in solubility should be noted, at mole fractions higher than roughly 0.8, the solubility decreases from PEC4 to PEC8 and, on the contrary, at lower mole fractions, the solubility increases from PEC4 to PEC8. It should be noted Fandiño et al [5] found similar behavior for the CO 2 -pentaerythritol tetravalerate (PEC5) system, in the temperature range between 283 K and 333 K. Using the determined parameters, the excess Gibbs energy, g E , was calculated from the equation,…”

“…Moreover, the regression of these models requires a large number of experimental data to determine the dependence of the solubility on pressure, temperature, and molecular structure. Unfortunately, in the literature there is a lack of such information, except for few systematic works, as [1][2][3][4][5][6][7]. For this reason, our group is involved in a research program to provide experimental measurements and the development of a general predictive model focused on the phase behavior of lubricant + refrigerant blends, with particular attention to systems of POE precursors and CO 2 [8][9][10][11][12][13][14].…”

Direct measurement of the heat of solution and solubility of carbon dioxide in 1-hexyl-3-methylimidazolium bis[trifluoromethylsulfonyl]amide and 1-octyl-3-methylimidazolium bis[trifluoromethylsulfonyl]amide

“…The gas solubility was also determined directly using a newly built experimental apparatus based on an isochoric saturation technique, similar to that used in our laboratory for high-precision, low-pressure gas solubility measurements (Jacquemin et al, 2006b) and to different high pressure cells described by other authors (Bobbo et al, 2007;Wahlström and Vamling, 1999;Fandiño et al, 2008). This experimental technique requires the precise knowledge of the vapor pressure of the liquid.…”

“…In order to estimate V ∞ 2 we have compared the results obtained from an empirical relation proposed by Kumelan et al (2009) for the system CO 2 + [C 6 mim][NTf 2 ] (uncertainty estimated as ±1 cm 3 mol −1 ) with other prediction models [Wahlström and Vamling (1999), Zellner et al (1970), and the correlation of Heidemann and Prausnitz (1977) based on the work of Lyckman et al (1965)] already evaluated by Fandiño et al (2008) for CO 2 + ester systems. Recommended equations in references (Wahlström and Vamling, 1999) and (Zellner et al, 1970) are independent of the solvents properties while the one proposed by Heidemann and Prausnitz (1977) requires the knowledge of the cohesive energy density of the solvent.…”