Solubility parameter of narrow oil cuts by several models: quantifying the discrepancy among predictions for heavy cuts

In this study, the performance of nine models was evaluated in predicting the solubility parameter of oil cuts. The oil cuts were generated from simulated distillation curves assuming a constant Watson factor. Five oils from different Brazilian geographic regions were used. It was observed that predictions diverge mainly for cuts having boiling points above 460 K. For instance, the maximum difference in the solubility parameter of the same cut can reach 9.8 MPa 1/2 depending on the model used. For extrapolated results, this difference can reach 17.6 MPa 1/2 . The coherence of model extrapolations for heavier cuts was also evaluated. Furthermore, the volume additivity hypothesis of the solubility parameter was also assessed by comparing volume-averaged solubility parameters with the corresponding bulk solubility parameter of oils. In general, it was found that volumetric additivity is an acceptable simplification and, for the same oil, the maximum difference between the two ways of calculating the oil solubility parameter did not exceed 1.4 MPa 1/2 .