NMR study of the composition of aqueous 2-aminoethanol solution used for absorption of carbon dioxide from fuel gases

Abstract

The compositions of aqueous 2-aminoethanol solutions used in industry for absorption of carbon dioxide resulting from combustion of natural gas have been determined by 1H and 13C NMR spectroscopy. The absorption process does not involve generally accepted paths of thermal decomposition of the absorbent in the reaction with carbon dioxide, but the main path is non-oxidative decomposition of 2-aminoethanol into ammonia and ethylene oxide. Splitting of the NMR signals of carbamate anion formed by reaction of 2-aminoethanol with carbon dioxide has been rationalized by specific structure of the anion due to intramolecular hydrogen bonding.