Prediction of the Basicity of Aqueous Amine Solutions and the Species Distribution in the Amine−H2O−CO2 System Using the COSMO-RS Method

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• 作者：Hidetaka Yamada ; Shinkichi Shimizu ; Hiromichi Okabe ; Yoichi Matsuzaki ; Firoz A. Chowdhury ; Yuichi Fujioka
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2010
• 出版时间：March 3, 2010
• 年：2010
• 卷：49
• 期：5
• 页码：2449-2455
• 全文大小：139K
• 年卷期：v.49,no.5(March 3, 2010)
• ISSN：1520-5045

文摘

A conductor-like screening model for real solvents (COSMO-RS) was applied to the study of the amine−H₂O−CO₂ system. pK_a values for 25 amines including a variety of alkanolamines and some cyclic or aromatic amines were calculated by the COSMO-RS method coupled with the density functional theory (DFT). The predictions of pK_a values were compared using different DFT levels for geometry optimization and also with those based on another solvation model (SM5.4/A). The DFT-COSMO calculation at the BP/TZVP level has shown a relatively good correlation with experimental values for the 25 amines (R² 0.8) at a low computational cost. With this method, we have developed a calculation model to predict the equilibrium ratio between carbamate and bicarbonate anions in a CO₂-loaded aqueous amine solution and have confirmed the validity of the prediction model by ¹³C NMR spectroscopy.