Experimental and Computational Study of CO2 Storage and Sequestration with Aqueous 2-Amino-2-hydroxymethyl-1,3-propanediol (TRIS) Solutions

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• 作者：Rama Oktavian ; Mohamed Taha ; Ming-Jer Lee
• 刊名：Journal of Physical Chemistry A
• 出版年：2014
• 出版时间：December 11, 2014
• 年：2014
• 卷：118
• 期：49
• 页码：11572-11582
• 全文大小：550K
• ISSN：1520-5215

文摘

Experimental solubility data of CO₂ in (5 and 10) mass% TRIS aqueous solutions were measured at (318.15 and 333.15) K and up to 10 MPa. The solubility data were well correlated with the modified Kent鈥揈isenberg model. The reaction mechanism, reaction energies, and equilibrium constants for the formation of bicarbonate and carbamate from CO₂, H₂O, and TRIS were studied using the quantum-chemical approach COSMO-RS (conductor-like screening model for real solvents) at the BP/TZVP level. The bicarbonate and carbamate formations were confirmed by using Fourier transform infrared (FTIR) spectroscopy. The results demonstrate that the formation of the bicarbonate anion is the main product formed by the direct reaction of CO₂ with water and TRIS, and reveal that the carbamate anion was formed by a proton transfer from TRIS鈥揅O₂ zwitterion to TRIS. Density functional theory (DFT) calculations with transition-state optimization and intrinsic reaction coordinate (IRC) in water using IEF-PCM solvation model at the B3LYP/6-311++G(d,p) levels of theory were employed to support the reaction pathway for the bicarbonate and carbamate formations. The conversion of the absorption product to stable carbonate (CaCO₃) was also investigated experimentally by adding various Ca²⁺ sources, CaCl₂路2H₂O aqueous solution, and artificial seawater.