Mechanisms of CO sub( 2) Capture into Monoethanolamine Solution with Different CO sub( 2) Loading during the Absorption/Desorption Processes

• Published in: Environmental science & technology 2015-09, Vol.49 (17), p.10728-10728
• Main Authors: Lv, Bihong, Guo, Bingsong, Zhou, Zuoming, Jing, Guohua
• Format: Article
• Language: English
• ISSN: 0013-936X

Though the mechanism of MEA-CO... system has been widely studied, there is few literature on the detailed mechanism of CO... capture into MEA solution with different CO... loading during absorption/desorption processes. To get a clear picture of the process mechanism, ...C nuclear magnetic resonance (NMR) was used to analyze the reaction intermediates under different CO... loadings and detailed mechanism on CO... absorption and desorption in MEA was evaluated in this work. The results demonstrated that the CO... absorption in MEA started with the formation of carbamate according to the zwitterion mechanism, followed by the hydration of CO... to form HCO.../CO..., and accompanied by the hydrolysis of carbamate. It is interesting to find that the existence of carbamate will be influenced by CO... loading and that it is rather unstable at high CO... loading. At low CO... loading, carbamate is formed fast by the reaction between CO... and MEA. At high CO... loading, it is formed by the reaction of CO.../CO... with MEA, and the formed carbamate can be easily hydrolyzed by H... Moreover, CO... desorption from the CO...-saturated MEA solution was proved to be a reverse process of absorption. Initially, some HCO... were heated to release CO... and other HCO... were reacted with carbamic acid (MEAH...) to form carbamate, and the carbamate was then decomposed to MEA and CO... (ProQuest: ... denotes formulae/symbols omitted.)