Development of a monoethanolamine/n-butanol biphasic solution with tunable phase separation for CO2 absorption via combined experimental and computational study: Role of solvation environment, phase separation mechanism

An energy-efficient monoethanolamine (MEA)/ n-butanol biphasic solution with tunable phase separation was proposed in this study. The effect of the solvation environment and the mechanism of the liquid–liquid phase separation were investigated systematically by both experimental study and molecular dynamics simulations. Experimental results showed that the concentration ratio of n-butanol and water played a significant role in the phase separation behavior and desorption performance, and can effectively reduce the heat duty of desorption. The mechanism of phase separation was obtained using 1 H NMR and molecular dynamics simulation, which was related to the strong strength of hydrogen bonds between MEAH + and H 2 O, MEACOO − and H 2 O, and the van der Waals forces between MEAH + and MEACOO − . In addition, the effect of the solvation environment on the phase separation was also attributed to the strong intermolecular interaction between MEAH + and MEACOO − . This study highlights the effect of the solvation environment on the tunable phase separation and the mechanism of phase separation for the further development of biphasic solutions.