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

Abstract

Carbon dioxide (CO 2 ) is one of the most promising natural refrigerants that can be employed as an alternative to hydrofluorocarbons (HFC), due to its low global warming potential (GWP). Nevertheless, CO 2 presents several technical problems when employed as a working fluid in refrigeration systems. In particular, the selection of the most suitable lubricant for each application is far from being resolved. The thermodynamic behavior of a CO 2 + lubricant system must be well-known for a correct oil selection. This work is part of a research project to study the solubility of CO 2 in commercial oils and their precursors. Here, solubility measurements of CO 2 in pure pentaerythritol tetrabutyrate (PEC4) between 243 K and 343 K are presented and compared with miscibility data of CO 2 in pentaerythritol tetrahexanoate (PEC6) and pentaerythritol tetraoctanoate (PEC8). The experimental data were correlated with a thermodynamic model based on a cubic equation of state with Huron-Vidal mixing rules and the UNIQUAC equation for the excess Gibbs energy at infinite pressure.

Solubility of trans-1,3,3,3-tetrafluoroprop-1-ene (R1234ze(E)) in pentaerythritol tetrapentanoate (PEC5) in the temperature range from 283.15 to 353.15 K

“…Therefore, to study the solubility of refrigerant in the compressor oil consisting of only one substance with a known structure has attracted more attention. In the past few years, many experimental investigations focused on the refrigerant in the precursors of synthetic oil have been reported (Bobbo et al, , 2008(Bobbo et al, , 2010Fedele et al, 2009aFedele et al, ,b, 2011Fandino et al, 2008Fandino et al, , 2010aPernechele et al, 2009;Vamling, 1999, 2000).…”

Solubility of Dimethyl Ether in Pentaerythritol Tetrahexanoate (PEC6) and in Pentaerythritol Tetraoctanoate (PEC8) Between (283.15 and 353.15) K

“… a The values from the Refprop 9.1 database b The values from Pernechele et al c Predicted by means of Nath and Yadava method …”

Experimental investigations for the phase equilibrium of R1234yf and R1234ze(E) with two linear chained pentaerythritol esters

“…Wahlstrom and Vamling [7,8] reported the solubilities of different HFCs, such as HFC134a, HFC152a, HFC32, HFC125, and HFC143a, in PEC5 and PEC9. Bobbo [9], Fandino [10][11][12], Fedele [13], and Pernechele [14] investigated the solubility of carbon dioxide in linear chained esters (PEC4-PEC9). They also measured the solubility data of carbon dioxide in branched chained and cyclic chained esters [10,15,16].…”