On the Applicability of the Regular Solution Theory to Asphaltene + Diluent Mixtures
Bibliographic record
Abstract
The similarity of the Hildebrand or Hansen solubility parameter is frequently used in petroleum science as a measure of the compatibility of constituents and for interpreting and correlating properties of asphaltene + diluent mixtures. A partial specific volume at near infinite dilution and enthalpies of solution are sensitive measures of solute–solvent interactions derived from high precision density and calorimetry measurements for dilute mixtures. In this contribution, the partial specific volumes and enthalpies of solution of pyrene and various Athabasca and Maya asphaltenes at near infinite dilution on a mole fraction basis, in decane, toluene, 1-methylnaphthalene, quinoline, anisole, 2,6-lutidine, pyridine, methylene chloride, and tetrahydrofuran are reported over the temperature range of 20–80 °C. At 20 °C, these diluents possess solubility parameters ranging from 15 MPa 0.5 (decane) to 22 MPa 0.5 (quinoline). The properties of pyrene + diluent mixtures are used to illustrate the application and misapplication of the regular solution theory to such mixtures. Thermodynamic measurements, partial specific volume, and enthalpy of solution are shown to be independent of both Hildebrand and Hansen solubility parameter values. These results do not support the use of the solubility parameter or other simple solution thermodynamic concepts to describe asphaltene + diluent mixture behavior. The need for a more detailed description of physiochemical phenomena arising upon mixing asphaltenes with diluents is discussed.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".