Solubility of hydrocarbons

The solubility of hydrocarbon liquids from the same chemical family diminishes as the molecular weight increases. This effect is particularly sensitive thus in the paraffin series, the solubility expressed in mole fraction is divided by a factor of about five when the number of carbon atoms is increased by one. The result is that heavy paraffin solubilities are extremely small. The polynuclear aromatics have high solubilities in water which makes it difficult to eliminate them by steam stripping. 

In the case of three-phase equilibria, it is also necessary to account for the solubility of hydrocarbon gases in water. This solubility is proportional to the partial pressure of the hydrocarbon or, more precisely, to its partial fugacity in the vapor phase. The relation which ties the solubility expressed in mole fraction to the fugacity is the following ... 

Solubility of hydrocarbon gases in water expressed as Henry s constants. 

For this problem, methanol had no practical effect on the solubility of hydrocarbons in the water phase (Figure 4). 

Ionic liquids are similar to dipolar, aprotic solvents and short-chain alcohols in their solvent characteristics. These vary with anion (from very ionic Cl to more covalent [BETI] ). IFs become more lipophilic with increasing alkyl substitution, resulting in increasing solubility of hydrocarbons and non-polar organics. 

Water Solubility of Hydrocarbon Components of Mineral Oil Hydraulic Fluids... 

Huibers, P. D. T., Katritzky, A. R., Correlation of the aqueous solubility of hydrocarbons and halogenated hydrocarbons with molecular structure, J. Chem. Inf. Comput. Sci. 1998, 38, 283-292. 

Al-Sahhaf, T. A. (1989) Prediction of the solubility of hydrocarbons in water using UNIFAC. J. Environ. Sci. Health A24, 49-56. 

Heidman, J. L., Tsonopoulos, C., Brady, C. J., Wilson, G. M. (1985) High-temperature mutual solubilities of hydrocarbons and water. AIChEJ. 31, 376-384. 

Kabadi, V. N., Danner, R. P. (1979) Nomograph solves for solubilities of hydrocarbons in water. Hydrocarbon Processing, 68, 245-246. 

Connolly, J.F. (1966) Solubility of hydrocarbons in water near the critical solution temperatures. J. Chem. Eng. Data 11, 13-16. 

Lande, S.S., Hagen, D.F., Seaver, A.E. (1985) Computation of total molecular surface area from gas phase ion mobility data and its correlation with aqueous solubilities of hydrocarbons. Environ. Toxicol. Chem. 4, 325-334. 

Leinonen, PJ. (1972) The Solubility of Hydrocarbons in Water. M.A.Sc. Thesis, University of Toronto, Toronto, Canada. 

Price, L.C. (1973) The Solubility of Hydrocarbons and Petroleum in Water. Ph.D. Thesis., University of California, Riverside, CA. Price, L.C. (1976) Aqueous solubility of petroleum as applied to its origin and primary migration. Am. Assoc. Petrol. Geol. Bull. 60, 213-244. 

Methanol has little effect on the predicted solubility of hydrocarbons in the liquid water phase. 

At temperatures well below UCST, solubilities of hydrocarbons in water or water in hydrocarbons drop to very low values. The solutions are very nearly ideal in the Henry s law sense, and the isotope effects on solubility can be directly interpreted as the isotope effect on the standard state partial molar free energy of transfer from the Raoult s law standard state to the Henry s law standard state. Good examples include the aqueous solutions of benzene, cyclohexane, toluene,... 

Wasik, S.P., Schwarz, F.P., Tewari. Y.B., and Miller, M.M. A head-space method for measuring activity coefficients, partition coefficients, and solubilities of hydrocarbons in saline solutions. J. Res. Nat. Bur. Stand., 89(3) 273-277, 1984. 

Some cosolvents can diminish the hydrophobic effect of water. For example, ethanol in water increases the solubility of hydrocarbons by helping to solvate them in preference to the poor solvation by water alone. 

Hemptinne, J.-C., H. Delepine, C. Jose, and J. Jose, Aqueous solubility of hydrocarbon mixtures , Revue de Vinstitut frangais du petrole, 53, 309-419 (1998). 

The low solubility of hydrocarbons in water, coupled to the fact that the first step in hydrocarbon degradation involves a membrane-bound oxygenase, makes it essential... 

Desired Effluent Quality. This is the single most important factor that decides the ultimate type/combination of equipment required. The criteria used in computing influent quality apply equally in establishing effluent quality Note that analyzers that use solvent-extraction principles measure soluble oil content also. Average solubility of hydrocarbons in water has typically been found to be 20 ppm in Bahrain oil fields. The results obtained with solvent-extraction methods on effluent samples shall be inclusive of dissolved hydrocarbons. For example, a 35-ppm result represents an effluent quality of IS ppm of free floatable od. 

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