Thermodynamic analysis of carbamate formation and carbon dioxide absorption in N-methylaminoethanol solution

Protonation and carbamate formation are critical reactions for CO 2 capture using amine-based absorbents which impact both CO 2 absorption and amine regeneration. In this regard, thermodynamic analysis towards CO 2 absorption in N -methylaminoethanol solution is carried out with specific attention to the corresponding protonation and carbamate formation reactions. The CO 2 absorption mechanism is investigated with the acquisition of reaction equilibrium constant and heat of reaction. CO 2 absorption performance of N -methylaminoethanol solution was evaluated in terms of CO 2 loading and solution pH. A thermodynamic model was then developed to mathematically describe the investigated system and make prediction on equilibrium CO 2 solubility, species profiles, and absorption/regeneration heat. Results show that the average relative deviation of equilibrium CO 2 solubility calculated from the is 4.2%. The predictive species profile and CO 2 absorption heat of N -methylaminoethanol solution indicates less energy cost to desorb CO 2 . This is in line with the relative unstable N -methylaminoethanol carbamate formation and consequential conversion to (bi)carbonate. The position of N -methylaminoethanol as a potential absorbent in amine based carbon capture is shown in terms of chemical reaction constants, equilibrium CO 2 solubility, second order rate constant ( k 2 ), and p Ka .