Influence of (phenol and sodium sulfate) on the solubility of carbon dioxide in water

Abstract

New experimental results are presented for the solubility and the partial molar volume of carbon dioxide in an aqueous solution of phenol and sodium sulfate at temperatures of about (314, 354, and 395)K and pressures up to about 10MPa. The composition of the solvent expressed as molality in water is about 0.5mol·(kgH2O)−1 for phenol as well as for sodium sulfate. 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 solutions of organic compounds. The experimental results are compared to prediction and correlation results from a thermodynamic model. That model is a combination of a model for the solubility of CO2 in aqueous solutions of sodium sulfate on one side and a model for the solubility of CO2 in aqueous solutions of phenol on the other side. When ternary interactions between CO2, phenol, and sodium sulfate are neglected, the model allows prediction of the pressure that is required to dissolve a given amount of CO2 in the mixed aqueous solution. The prediction results reveal a reasonable agreement. However (and as in previous investigations with N,N-dimethylformamide instead of phenol as the organic solvent component or with sodium chloride instead of sodium sulfate as the dissolved electrolyte) adjusting a ternary parameter for interactions between the three solutes (i.e., CO2, phenol, and sodium sulfate) results in a correlation that allows description of the new experimental results almost within experimental uncertainty.