Density and viscosity of the binary polyethylene glycol/CO2 systems

Abstract

Density of CO2 saturated solutions of polyethylene glycols (PEGs) of different molecular weight was measured in pressure range from 8.0MPa up to 47.7MPa at a temperature of 343K by a volumetric method. To validate the method density of pure CO2 was measured at different pressures and a temperature of 293K. The results were compared to the literature data and the accuracy was better than 2%. The density was between 1.17g/mL for PEG 1000/CO2 at 14.5MPa and 1.78g/mL for the system PEG 4000/CO2 at 35MPa. Further, the data were compared to results, obtained by a gravimetric method using magnetic suspension balance (MSB).Viscosity of CO2 saturated solutions of polyethylene glycols (PEGs) of different molecular weight at different pressures and at a temperature of 343K was measured using a high pressure view cell. Also a temperature impact on the viscosity of pure PEGs was observed at ambient pressure. After saturating PEG 1500 with 10MPa of CO2 pressure its viscosity decreases from 76.6mPas to 2.24mPas at 333K. Further addition of CO2 and increasing the pressure results in even lower viscosity and the highest viscosity reduction was reached at the highest pressure; at 35MPa viscosity of the system PEG 1500/CO2 is only 0.665mPas.