Experimental and Modeling Study on Data of Toluene, Cyclohexane, and n-Pentane in Water

The release of crude oil called an oil spill containing large amounts of liquid hydrocarbons in the environment, particularly the marine ecosystem, is the reason for a variety of pollutions. Also, in petrochemical plants and refineries, the organic liquid hydrocarbons have to be removed from the wastewater streams in the strippers and liquid–liquid extractors. Therefore, sufficient experimental liquid hydrocarbon + water data in quantity as well as quality is essential to evaluate the amounts of liquid hydrocarbons in water and extend thermodynamic models. In this contribution, the solubilities of n-pentane (from the paraffinic group), cyclohexane (from the naphthenic group), and toluene (from the aromatic group) in water at a pressure of 0.1 MPa and in the temperature range 278.15–323.15 K have been experimentally measured. Thereupon, a simple theoretical-based correlation was proposed to compute the solubilities of liquid hydrocarbon in water based on the dependency of solubility on the heat of the solution. The average absolute relative deviations (AARDs) of the model for solubilities (mole fractions) of n-pentane, toluene, and cyclohexane in water were 1.40%, 2.74%, and 1.14%, respectively. Finally, the activity coefficients of liquid hydrocarbons in water at infinite dilution, the heat of the solution, the heat capacity of the solution, and the minimum solubility temperature were calculated and compared with the existing experimental data in the literature, and acceptable agreement was observed.