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

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 H-1 and C-13 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.