Vapor–Liquid Equilibrium for Mixtures of Ethylethylenediamine, Ethylenediamine, and Water

Abstract

The temperature and the composition of the vapor and liquid phases at equilibrium were measured at atmospheric pressure and (50 and 20) kPa for the binary mixtures: water (1) and ethylenediamine (2, EDA); water and ethylethylenediamine (3, EtEDA); and EDA and EtEDA. For the ternary mixture of water, EDA, and EtEDA, equilibrium conditions were measured at atmospheric pressure. The vapor pressure of EtEDA was measured in the temperature range from (358 to 402) K, and Antoine parameters were fitted to the data. Parameters for the universal quasichemical (UNIQUAC) equation are estimated from binary data and applied to the ternary mixture. It was shown that the mixture of EDA and EtEDA has a zeotropic pinch close to pure EDA. Furthermore, it was found that the ternary mixture has a saddle point azeotrope at a molar fraction of 0.24 of water, 0.62 of EDA, and 0.14 of EtEDA and a temperature of 392.6 K at atmospheric pressure. Thus, the volatility between EDA and EtEDA is reversed in the water-rich region, and EtEDA is the most volatile component close to the binary azeotrope between water and EDA. This is illustrated by univolatility lines in a ternary diagram.

Electrical power production from low-grade waste heat using a thermally regenerative ethylenediamine battery

“…The ethylenediamine-water mixture has an azeotrope with a maximum separation point of 0.55 (molar fraction), so the fractional distillation proposed for TRAB could not be used for a TRENB [27][28][29]. Therefore, other separation methods, such as an azeotropic distillation or pressure swing distillation would need to be used to separate ethylenediamine and water using waste heat.…”

An Electrochemically Mediated Amine Regeneration Process with a Mixed Absorbent for Postcombustion CO2 Capture

“…One of these factors that could potentially raise concern when running the process long-term on a large scale is the high vapor pressure of EDA. The vapor pressure of a pure EDA solution at 20 °C is 1.3 kPa, which is comparable with that of water (2.3 kPa) at the same temperature . This negatively affects the process performance by reducing the absorbent CO 2 capacity and increasing the energetics, since EDA vapor would leave the system through the absorbent gas phase effluent over time.…”

“…The vapor pressure of a pure EDA solution at 20 °C is 1.3 kPa, which is comparable with that of water (2.3 kPa) at the same temperature. 22 This negatively affects the process performance by reducing the absorbent CO 2 capacity and increasing the energetics, since EDA vapor would leave the system through the absorbent gas phase effluent over time. In this study, we investigated the possibility of using a mixture of EDA and another amine with a lower vapor pressure to reduce the absorbent vapor pressure, minimizing absorbent loss.…”

Thermodynamic modeling of binary mixtures of ethylenediamine with water, methanol, ethanol, and 2-propanol by association theory

“…The VLE of EDA–water was satisfactorily modeled by universal quasichemical (UNIQUAC) 11 equation at various pressures. 12 The VLE of binary mixtures of several diamines with water was correctly modeled by the method of Barker which is based on the excess Gibbs function. 13 Regarding binary mixtures of EDA with alcohols, Kato et al 14 reported the experimental VLE data for EDA and dipropylamine with methanol, ethanol, and 2-propanol; the VLE data were correlated by Wilson 15 equation.…”