McCann Nichola, Phan Duong, Wang Xiaoguang, Conway William, Burns Robert, Attalla Moetaz, Puxty Graeme, Maeder Marcel
Department of Chemistry, The University of Newcastle, Newcastle NSW 2308, Australia.
J Phys Chem A. 2009 Apr 30;113(17):5022-9. doi: 10.1021/jp810564z.
Removal of carbon dioxide from fossil-based power generation is a potentially useful technique for the reduction of greenhouse gas emissions. Reversible interaction with aqueous amine solutions is most promising. In this process, the formation of carbamates is an important reaction of carbon dioxide. In this contribution, a detailed molecular reaction mechanism for the carbamate formation between MEA (monoethanolamine) and dissolved CO(2) as well as carbonate species in aqueous solution is presented. There are three parallel, reversible reactions of the free amine with CO(2), carbonic acid, and the bicarbonate ion; the relative importance of the three paths is strongly pH dependent. Kinetic and equilibrium measurements are based on (1)H NMR and stopped-flow measurements with rate constants, equilibrium constants, and protonation constants being reported.
从基于化石燃料的发电过程中去除二氧化碳是一种减少温室气体排放的潜在有用技术。与胺水溶液的可逆相互作用最具前景。在此过程中，氨基甲酸盐的形成是二氧化碳的一个重要反应。在本论文中，提出了单乙醇胺（MEA）与溶解的CO₂以及水溶液中的碳酸盐物种之间形成氨基甲酸盐的详细分子反应机理。游离胺与CO₂、碳酸和碳酸氢根离子存在三个平行的可逆反应；这三条反应路径的相对重要性强烈依赖于pH值。动力学和平衡测量基于¹H NMR和停流测量，并报告了速率常数、平衡常数和质子化常数。
