Carbon dioxide solubility was studied in 3.5 m (23.5 wt %) morpholine (MOR), 17.7 m (65 wt %) 2-aminoethoxyethanol (diglycolamine or DGA), and 3.6 m MOR + 14.7 m DGA (11 wt % MOR + 53 wt % DGA). CO2 solubility was determined by dynamic measurements with a wetted wall contactor. Carbamate and bicarbonate concentrations were determined by 13C NMR in solutions loaded with 13CO2. The data are represented by the electrolyte NRTL model. At a given CO2 loading (mol/mol amine), the CO2 vapor pressure over 3.5 m MOR is 10 to 1000 times greater than 17.7 m DGA. In 3.6 m MOR + 14.7 m DGA, the CO2 vapor pressure is 5 to 7 times greater than in 17.7 m DGA at high CO2 loading, but the same below 0.2 loading. MOR carbamate is less stable than DGA carbamate by a factor of 7 to 10 from (300 to 333) K. The model predicts that MOR vapor pressure is 100 times greater than DGA over 3.6 m MOR + 14.7 m DGA from (313 to 333) K. The heat of CO2 absorption in the blend is equivalent to 17.7 m DGA up to 0.35 loading but is 40 % lower at 0.5 loading. The working capacity of the blend is 17 % less than 17.7 m DGA.
Compounds
#
Formula
Name
1
C4H11NO2
2-(2-aminoethoxy)ethanol
2
C4H9NO
tetrahydro-1,4-oxazine
3
H2O
water
4
CO2
carbon dioxide
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.