Densities, viscosities and spectroscopic study of partially CO2-loaded nonaqueous blends of 2-butoxyethanol with 2-(ethylamino)ethanol and 2-(butylamino)ethanol at temperatures of (293.15 to 353.15) K

Abstract

Nonaqueous CO2 absorbents, composed of secondary alkanolamines and 2-alkoxyethanols, have attracted much attention for an energy-efficient CO2 capture process. In this work, densities and viscosities of partially CO2-loaded mixtures of 2-(butylamino)ethanol (BAE) + 2-butoxyethanol (EGBE) and 2-(ethylamino)ethanol (EAE) + EGBE were measured at atmospheric pressure over the temperature range of (293.15 to 353.15) K with amine mass fraction (w1) of (0.10, 0.30 and 0.50) containing various CO2 loading. With increasing CO2 loadings, significant increases in both density and viscosity were observed. Dimensionless ρloaded·ρCO2-free−1 and ηloaded·ηCO2-free−1 from the CO2-free and CO2-loaded systems were fitted by proposed correlations as a function of temperature, amine concentration and CO2 loading. The calculated values of density and viscosity from the correlations are in good agreement with the experimental results, with AADs within 0.15% and 1.60% for density and viscosity respectively. The dramatic increase in viscosity of carbonated solutions was interpreted by the intermolecular interactions and the formation of ionic products in the mixtures based on the FTIR spectral results.