This work presents new experimental results for carbon dioxide (CO2) solubility in aqueous piperazine (PZ) in the temperature range of (298 to 328) K and CO2 partial pressure of about (0.1 to 1500) kPa. The concentrations of the aqueous PZ were in the range of about (0.2 to 4.5) M. A thermodynamic model based on electrolyte nonrandom two-liquid (ENRTL) theory has been developed to correlate and predict the vapour liquid equilibrium (VLE) of CO2 in aqueous PZ. The model predictions have been in good agreement with the experimental data of CO2 solubility in aqueous blends of this work as well as those reported in the literature. It is observed that, at low temperature (up to 333 K) and low PZ concentration, using regressed ENRTL interaction parameters and Henry's constant of CO2 in water is sufficient to predict VLE of CO2 in aqueous PZ. However, at high temperature and high PZ concentration, it is required to adjust Henry's law constant in aqueous solution of PZ for better prediction of CO2 partial pressure over aqueous PZ solution. The current model can also predict speciation, heat of absorption, pH of the loaded solution, and PZ volatility.
Compounds
#
Formula
Name
1
C4H10N2
piperazine
2
CO2
carbon dioxide
3
H2O
water
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.