Influence of poly(ethylene oxide) 400 (PEG400) on the absorption of CO 2 in diethanolamine (DEA)/H2O systems
Résumé
An experimental device coupling vapor-liquid equilibrium (VLE) measurements and liquid phase analysis by Fourier transform infrared (FTIR) spectroscopy has been used to study the absorption of CO2 in water/diethanolamine (DEA)/poly(ethylene oxide) 400 (PEG400) systems. The concentration of the molecular form of absorbed CO2 and the evolution of the carbamate species are measured with the IR spectroscopic method. The partial pressure of carbon dioxide and the liquid phase speciation have been determined at T = 298.1 K for various PEG400 concentrations (with a mass fraction ranging from 0 to 0.3), the mass fraction of DEA being 0.3. At fixed pressure, the CO2 solubility decreases for increasing PEG400 concentrations, which expresses the decrease in solvent polarity. For a given loading and at constant concentration of DEA, the CO2 molecular concentration increases with the PEG400 concentration increase, whereas the ion repartition is not significantly influenced by the solvent composition. © 2011 American Chemical Society.