Kinetics of Carbon Dioxide Removal by n-Propyl- and n-Butylmonoethanolamine in Aqueous Solutions

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• 作者：Ravindra B. Kanawade ; Prakash D. Vaidya ; K. Subramanian ; Vijay V. Kulkarni ; Eugeny Y. Kenig
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：June 16, 2016
• 年：2016
• 卷：30
• 期：6
• 页码：5077-5082
• 全文大小：315K
• 年卷期：0
• ISSN：1520-5029

文摘

Secondary alkanolamines associated with an alkyl group are potentially attractive post-combustion CO₂-capturing solvents. Their reactivity with CO₂ is influenced by the nature of the alkyl group that substitutes the hydrogen atom of the amino functional group. In the present work, we measured the rates of CO₂ absorption into aqueous solutions of n-propylmonoethanolamine (PMEA) and n-butylmonoethanolamine (BMEA) in a stirred-cell reactor under fast pseudo-first-order conditions. The concentrations of PMEA and BMEA in the water solutions were changed in the 2–3 kmol m^–3 range. It was discovered that, unlike the usual amines, PMEA and BMEA followed overall third-order kinetics. We evaluated the reaction rate constants at different temperatures, viz., 303, 308, and 313 K, and discovered that PMEA reacts with CO₂ faster than BMEA. Furthermore, we gave an interpretation of the kinetic data using the zwitterion and termolecular mechanisms. Finally, a comparison of the efficacy of the investigated solvents with N-methylmonoethanolamine (MMEA) and N-ethylmonoethanolamine (EMEA) was accomplished. It was found that reactivity of amines diminished in the order EMEA > MMEA > PMEA > BMEA.