An experimental investigation on the influence of NaCl on the solubility of CO2 in (water + phenol)

• Solubility pressures for CO2 in an aqueous solution of (phenol + NaCl) at 314 K, 354 K and 395 K.
• Solvent composition: molality of phenol: 0.5; molality of NaCl: 1.0.
• Pressures up to 10 MPa.
• Henry’s constant and partial molar volume of CO2 at infinite dilution in the solvent.
• Modelling (prediction/correlation).

New experimental results are presented for the solubility and the partial molar volume of carbon dioxide in an aqueous solution of phenol and sodium chloride at temperatures of about (314, 354 and 395) K and pressures up to about 10 MPa. The composition of the solvent – expressed as molality in water – is about 0.5 mol/(kg H2O) for phenol and 1 mol/(kg H2O) for sodium chloride. The experimental work is a continuation of investigations on the influence of organic components and strong electrolytes on the solubility of carbon dioxide in water. It extends a data base for developing and testing thermodynamic models to describe the solubility of gases in salt-free and salt-containing aqueous solvents mixed with organic compounds. The experimental results are compared to predictions and correlations from a thermodynamic model which combines a model for the solubility of CO2 in aqueous solutions of NaCl with a model for the solubility of CO2 in aqueous solutions of phenol. The prediction results reveal a reasonable agreement. As in a previous investigation – with N,N-dimethylformamide instead of phenol as the organic solvent component – adjusting a ternary parameter for interactions between the three solutes (i.e. CO2, NaCl, and phenol) results in a correlation that allows to describe the new experimental data within experimental uncertainty.

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