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

Abstract

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