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.