Liquid density, viscosity, surface tension, and spectroscopic investigation of 1,2-ethanediamine + 1,2-propanediol for CO2 capture

Liquid densities, viscosities, and surface tensions play significant roles in fluid flow and industrial applications for CO2 capture. These data of 1,2-ethanediamine (EDA) + 1,2-propanediol (PPD) binary system were measured under atmospheric pressure at T = (293.15 to 318.15) K throughout the entire concentration range. According to the experimental viscosities and densities, the viscosity deviation and excess molar volume values were respectively calculated, and the Redlich-Kister equation was used to fit the coefficients and to evaluate the deviations. The system exhibited negative excess molar volume values with a minimum at x1 ≈ 0.54 at experimental temperatures, and a maximum was found at x1 ≈ 0.76 for viscosity deviation. The solubility of CO2 was measured at different flow rates, and the maximum solubility was about 0.57 g CO2 per 1 g EDA + PPD system at 250 mL/min CO2 flow rate. Furthermore, the intermolecular interaction of PPD with EDA was systemically discussed according to FTIR, UV-Vis, 1H NMR, and fluorescence spectral results, surface tension, and electrical conductivity data, and it was expressed as the form of HO-CH2(CH3)CH2O-H·NH2CH2CH2N(H2).