1 research outputs found
NMR-Based Carbamate Decomposition Constants of Linear Primary Alkanolamines for CO<sub>2</sub> Capture
The
amine carbamate related equilibrium (RNHCOO<sup>–</sup> + H<sub>2</sub>O ⇆ RNH<sub>2</sub> + HCO<sub>3</sub><sup>–</sup>) has been investigated with <sup>13</sup>C NMR (Nuclear
Magnetic Resonance) spectroscopy for a series of linear primary alkanolamines,
and the apparent carbamate decomposition equilibrium constants have
been estimated. A quantitative NMR method for the calculation of the
concentration of the species formed in solution has been provided,
including the assessment of each of the fast exchanging proton species
(whose nuclei resonate at the same chemical shifts in the NMR spectra).
For this purpose, NMR-based calibration curves were utilized and an
alternative method was applied for validation. The overall results
showed that the amount of carbamate found at the equilibrium decreased
as the length of the carbon chain increased, while the corresponding
apparent carbamate decomposition equilibrium constants featured the
same order of magnitude (10<sup>–2</sup>)