Abstract : This article contributes to the development of a thermodynamic model for simulating CO2 solubility in pure water and aqueous brines under different conditions of temperature, pressure and ionic strength. The modeling activity-fugacity (γ-φ) approach allows calculating CO2 solubility, based on the Pitzer electrolyte theory for activity coefficient and Peng-Robinson's equation of state for fugacity. The present work proposes a new set of Pitzer interaction parameters through the set of CO2 solubility data in saline systems such as CO2-H2O-NaCl and CO2-H2O-Na2SO4. The determined model is capable of covering a wide T − P − I range (273.15–473.15 K, 0.1–40 MPa and 0–6 mol/kg). Average absolute deviation of CO2 solubility is about 5% compared to a large number of experimental data available (more than 700 data analyzed). New experimental solubility data for the CO2-H2O-NaCl-Na2SO4 system were also acquired in this study (303.15–423.15 K, 1.5–20 MPa and 0–6 mol/kg) to test the model's capacity: it is able to describe the CO2 solubility in aqueous salt mixtures without any further optimizations of interaction parameters.
https://hal-insu.archives-ouvertes.fr/insu-03315806 Contributor : Nathalie PothierConnect in order to contact the contributor Submitted on : Friday, August 6, 2021 - 7:36:51 AM Last modification on : Wednesday, November 17, 2021 - 12:33:30 PM Long-term archiving on: : Sunday, November 7, 2021 - 6:21:40 PM
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Pedro dos Santos, Laurent André, Marion Ducousso, Arnault Lassin, François Contamine, et al.. An improved model for CO2 solubility in aqueous Na+–Cl−–SO42− systems up to 473.15 K and 40 MPa. Chemical Geology, Elsevier, 2021, 582, pp.120443. ⟨10.1016/j.chemgeo.2021.120443⟩. ⟨insu-03315806⟩