13C NMR study on carbamate hydrolysis reactions in aqueous amine/CO2 solutions

Sakurako Wada, Takayuki Kushida, Haruna Itagaki, Toshimichi Shibue, Haruna Kadowaki, Jun Arakawa, Yukio Furukawa*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Carbamates of primary or secondary amines play a central role in amine CO2 absorbents. The equilibrium constant of a carbamate hydrolysis reaction, Kch, is important for evaluating the performance of absorbents. However, few Kch values have been reported to date. We determined the Kch values of normal amines, such as monoethanolamine (MEA), diethanolamine (DEA), and hindered amines, such as 2-amino-2-methyl-1-propanol (AMP) and 2-(isopropylamino)ethanol (IPAE), using a method involving a combination of 13C NMR spectroscopy and a chemical equilibrium analysis. The Gibbs energy changes derived from Kch for AMP and IPAE at 25 °C were negative, whereas those for normal amines, MEA and DEA, were positive. These properties are characteristic of hindered amines. We determined the standard enthalpy and entropy changes of the carbamate hydrolysis reactions from the temperature dependence of the equilibrium constant. The equilibrium constants and standard enthalpies obtained using the present method will be valuable for evaluating the performance of amine CO2 absorbents.

Original languageEnglish
Article number103175
JournalInternational Journal of Greenhouse Gas Control
Publication statusPublished - 2021 Jan


  • AMP
  • C NMR
  • Carbamate
  • Carbon dioxide
  • Enthalpy
  • Entropy
  • Equilibrium constant
  • Gibbs energy
  • Hydrolysis
  • IPAE

ASJC Scopus subject areas

  • Pollution
  • Energy(all)
  • Management, Monitoring, Policy and Law
  • Industrial and Manufacturing Engineering


Dive into the research topics of '13C NMR study on carbamate hydrolysis reactions in aqueous amine/CO2 solutions'. Together they form a unique fingerprint.

Cite this