Study on carbamate stability in the Amp/CO2/H2O system from 13C-NMR spectroscopy

Qualitative and quantitative 13C NMR studies were performed on 30 wt % aqueous solution of 2-amino-2-methyl-1-propanol (AMP) with different amount of CO2 at 25 °C. The results suggested that the main species in this system are: AMP/AMPH+, AMPCO2− and HCO3−/CO32−. The carbamate was observed at low loading and the carbamate stability constant was calculated based only on the experimental species concentration from NMR analysis. Based on the liquid phase speciation from NMR, the carbamate stability constant on mol fraction basis was found to be about 0.47 at 25 °C.