Systematic Investigation of the Thermodynamic Properties of Amine Solvents for CO₂ Chemical Absorption Using the Cluster-Continuum Model Systematic Investigation of the Thermodynamic Properties of Amine Solvents for CO<sub>2</sub> Chemical Absorption Using the Cluster-Continuum Model

Access this Article

Search this Article

Author(s)

Abstract

<p>Accurate condensed-phase quantum chemical calculations employing the continuum cluster model were undertaken to systematically examine the reactivity of amine solvents with CO<sub>2</sub>, a reaction of great importance in CO<sub>2</sub> capture and storage technologies. Thirteen amine compounds, including primary, secondary, tertiary, and hindered amines, were considered, and up to ten solvent water molecules were modeled explicitly including continuum solvation. Amine p<i>K</i><sub>a</sub> values and reaction Gibbs energies for the formation of bicarbonate, carbamate, and zwitterions were evaluated. Our calculations indicate that increasing the number of explicit water solvents (<i>n</i>) steadily improves computational accuracy, reducing the mean absolute deviation (MAD) of the calculated p<i>K</i><sub>a</sub> from the experimental values, i.e., 13.0, 8.6, 1.3, and 0.9 (in p<i>K</i><sub>a</sub> units) at <i>n</i> = 0, 1, 6, and 10, respectively. Reaction Gibbs energies calculated with large <i>n</i> for the studied reactions were consistent with the experimental observation that carbamates are the most stable product species, although their stability is lower for secondary amines. However, at <i>n</i> = 0 or 1, positive reaction Gibbs energies were predicted, suggesting that bicarbonate formation would not occur. These results strongly indicate that the trend in the reactivity of CO<sub>2</sub>-amine reactions can only be correctly predicted by modeling solute-solvent interactions accurately.</p>

Journal

  • Bulletin of the Chemical Society of Japan

    Bulletin of the Chemical Society of Japan 90(4), 451-460, 2017

    The Chemical Society of Japan

Codes

  • NII Article ID (NAID)
    130006770731
  • NII NACSIS-CAT ID (NCID)
    AA00580132
  • Text Lang
    ENG
  • ISSN
    0009-2673
  • NDL Article ID
    028108461
  • NDL Call No.
    Z53-B35
  • Data Source
    NDL  J-STAGE 
Page Top