Determination and modeling of solubility of CO2 in PEG200 + 1-pentanol and PEG200 + 1-octanol mixtures

The solubility of CO2 in poly(ethylene glycol)200 (PEG200, PEG with an average molecular weight of 200 g mol −1 ), 1-pentanol, 1-octanol, PEG200 + 1-pentanol, and PEG200 + 1-octanol was determined at 303.15, 313.15, and 323.15 K up to 8.0 MPa. It was demonstrated that the solubility increased with increasing pressure and concentration of the alcohols in the mixed solvents, and decreased as temperature was increased. The solubility of CO2 in PEG200 + 1-pentanol was larger than that in PEG200 + 1-pentanol at the same condition. The models to estimate the critical temperature (Tc), critical pressure (Pc), and acentric factor (ω) of PEG were developed on the basis of group contribution principle, and the parameters of PEG200 were estimated using these models. The solubility of CO2 in the solvents was calculated using Peng–Robinson equation of state (PR-EOS) and the Tc, Pc, and ω data were estimated in this work. It was shown that the data calculated agree satisfactorily with the experimental results. © 2007 Elsevier B.V. All rights reserved.

[1]  K. Matsuyama,et al.  Solubilities of poly(ethylene glycol)s in the mixtures of supercritical carbon dioxide and cosolvent , 1999 .

[2]  Ding-Yu Peng,et al.  A group-contribution correlation for predicting the acentric factors of organic compounds , 1993 .

[3]  Weize Wu,et al.  Tri-phase behavior of ionic liquid–water–CO2 system at elevated pressures , 2004 .

[4]  M. N. D. Ponte,et al.  High pressure phase equilibria for poly(ethylene glycol)s + CO2: experimental results and modelling , 1999 .

[5]  D. Peng,et al.  A New Two-Constant Equation of State , 1976 .

[6]  E. Weidner,et al.  Measurement and modelling of high-pressure phase equilibria in the systems polyethyleneglycol (PEG)–propane, PEG–nitrogen and PEG–carbon dioxide , 2000 .

[7]  R. Reid,et al.  The Properties of Gases and Liquids , 1977 .

[8]  S. Sandler.  Models for Thermodynamic and Phase Equilibria Calculations , 1993 .

[9]  A. Ramos,et al.  On the effect of polymer fractionation on phase equilibrium in CO2+poly(ethylene glycol)s systems , 2000 .

[10]  L. Doraiswamy,et al.  Phase Transfer Catalysis: Chemistry and Engineering , 1998 .

[11]  Effect of aqueous PEG or PPG solvents on reaction selectivity and Gibbs energies , 2004 .

[12]  R. P. Swatloski,et al.  Application of Poly(ethylene glycol)-based Aqueous Biphasic Systems as Reaction and Reactive Extraction Media , 2004 .

[13]  T. Tsuji,et al.  Vapor−Liquid Equilibria of the Three Binary Systems: Water + Tetraethylene Glygol (TEG), Ethanol + TEG, and 2-Propanol + TEG , 1998 .