Thermodynamics of CO2 reaction with methylamine in aqueous solution: A computational study

Document Type : Research Paper




Separation and capture of carbon dioxide from the flue gas of power plants in order to reduce
environmental damages has always been of interest to researchers. In this study, aqueous solution of
methylamine was used as an absorbent for CO2 capture. In order to study this reaction, Density
Functional Theory (DFT) was employed at the level of B3LYP/6-311++G(d,p) by using the
conductor-like polarizable continuum model (CPCM). Two possible reaction products were studied:
carbamate ion and bicarbonate ion. The estimation of the thermodynamic parameters indicated that
the reaction of bicarbonate ion forming is not thermodynamically feasible at room temperature.
However, the reaction of carbamate ion formation is exothermic (ΔH= -12.4 kcal mol-1) and
exergonic (ΔG= -1.48 kcal mol-1). Also, various atomic radii were employed to build up the solute
cavity within CPCM model and the effects of the solute cavity on the thermodynamic properties of
the reaction were studied.