Full text loading...
-
Experimental CO2 Solubility in Nacl-Cacl2 Brines At 333.15 and 453.15 K Up to 40 Mpa
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 1st Geoscience & Engineering in Energy Transition Conference, Nov 2020, Volume 2020, p.1 - 5
Abstract
Summary
As part of the global efforts for renewable energies development, CO₂ solubility measurements were provided for the geothermal industry. Solubility is obtained at high pressures (6–40 MPa), in aqueous phases reproducing the exploited geothermal resources, through NaCl and CaCl₂ synthetic brines (1.2 mol NaCl/kg H₂O and 0.2 mol CaCl₂/kg H₂O), at 333.15 and 453.15 K. This work is encouraged by the lack of literature measurements on CO₂ solubility at these experimental conditions. Both mixed-salts and single-salt brines are analysed for the production of original results. A new stirred reactor, with variable volume, was conceived to maintain gas-liquid equilibria, while solubility measurements were performed by titration. The experimental methods were validated with measures in pure water, at 333.15 K, as well as in NaCl and CaCl₂ single-salt brines (1 mol.kg H₂O), at 323.15 K. Then, twenty original measures were produced with their uncertainty, and compared to Phreeqc (Pitzer.dat) calculation results. The measurements highlight that CO₂ solubility decreases when the aqueous phase salinity increases. Finally, a discussion is proposed to determine if this salting-out effect is influenced mostly by the NaCl or the CaCl₂, when observed in the mixed-salts brines at 333.15 K.
© EAGE Publications BV