Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

CO2 solubility in formation water under sequestration conditions

Ahmadi, Pezhman, Chapoy, Antonin
Fluid Phase Equilib. 2018, 463, 80-90
ABSTRACT
A high pressure experimental setup was used to measure the solubility of CO2 in an aqueous solution of different salts (salinity: ~80000 ppm) at temperatures from (300 to 424) K and pressures up to 41 MPa. To ensure the validity of the experimental results and procedures, CO2 solubilities in deionised water were measured at the same pressure and temperature conditions. For both cases, experimental results were compared against predictions of the simplified cubic plus assocation equation of state (sCPA-EoS) [1] and Duan model [2]. Furthermore, the measured solubilities in deionised water were compared with literature experimental data. The average absolute deviation (%AAD) of all the measured solubilities in the mixed salts aqueous solution in comparison with predictions of the sCPA-EoS and Duan model were found to be 6.88 % and 4.04 %, respectively. A similar comparison was also performed for the measured CO2 solubilities in deionised water. The average absolute deviation between experimental results and predictions of the sCPA-EoS and Duan model were calculated to be 7.74 % and 4.19 %, respectively. The percentage average expanded uncertainty (with 95 % level of confidence, k=2) for measurements conducted in deionised water and mixed salt aqueous solution were found to be 1.20 % and 1.57 %, respectively.
Compounds
# Formula Name
1 CO2 carbon dioxide
2 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.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Gas
  • 4-L gasometer (Vinci Technologies)
  • 29