Solubility Parameters of Crude Oils and Asphaltenes

Abstract

Results obtained with flocculation threshold experiments and with inverse gas chromatography were used to validate the use of the solubility parameter approach to asphaltene flocculation phenomena. It was found that values of solubility parameters obtained with both methods are in good agreement. The global solubility parameter of the crude oils was factorized in terms of Linear Solvation Energy Relationship (LSER) coefficients corresponding to a given fluid. Results confirm the validity of the three-dimensional solubility parameter proposed by Hansen to deal with petroleum fluids.

Quantitative distinction of thermodynamic soluble and miscible states

“…Given that the bottom limit of the solubility has been obtained, it is necessary to explore the upper limit for the quantification of the solubility. In accordance to the previous study, the flocculation usually occurs when the value of the Flory–Huggins interaction parameter is greater than 0.5 40 . Thus, the upper limit of the solubility is inferred to be at the condition of χ 12 ≤ 0.5.…”

Measurement of activity coefficients at infinite dilution in 1-hexadecyl-3-methylimidazolium tetrafluoroborate ionic liquid

“…Such a theory has however been frequently used in non-regular solutions to elaborate thermodynamic models. As an example, this concept has been used to predict phase behavior of ionic liquids [22,23], of inorganic salts [24], and of asphaltene [25,26]. Hildebrand postulated that the maximum of solubility is observed when the solute and solvent cohesive energy densities are identical.…”

Estimation of solubility parameter by the modified ER equation of state

“…(5) and (6) calculated by the DE optimization technique for 11 groups of organic substances and 2 petroleum sub-fractions are illustrated in Table 5. The experimental data for solubility parameters of resins and asphaltenes were selected from various oil fields including Cold Lake, Indonesian, Athabasca, Orinoco, West Texas and some others [59][60][61][62][63][64][65][66]. This table also shows the number of iterations and the time spent on each optimization procedure.…”

“…(5) and (6) (NP = 50, F = 2, CR = 0.8) (experimental solubility parameter values used in optimization process from Refs. [6,34,36,38,[59][60][61][62][63][64][65][66] Therefore, one is able to apply the model parameter values in Table 5 for Eqs. (5) and (6) to estimate the total Hansen solubility parameters of large groups of substances instead of using complex thermodynamic models (e.g.…”