Impact of Asphaltenes and Naphthenic Amphiphiles on the Phase Behavior of Solvent−Bitumen−Water Systems
Bibliographic record
Abstract
A limiting factor impacting the quality and recovery of bitumen from oil sand operations is the formation of stable water-in-oil (w/o) and/or oil-in-water (o/w) emulsions during froth treatment. In a previous study, the impact of asphaltene partitioning on oil−water phase separation from the resulting emulsified phases (rag layers) was evaluated as a function of the solvent−bitumen−water ratio, temperature, and solvent aromaticity. In this work, the added effect of naphthenic amphiphiles at concentrations of 3 and 10 wt % on oil−water phase separation from similarly formulated rag layers is assessed. The observed phase behavior of these rag layers is discussed in view of interfacial coadsorption mechanisms proposed in the literature. A major finding is that, under alkaline process conditions, an increase in the concentration of sodium naphthenates (NaNs), produced as a result of naphthenic amphiphile dissociation, promotes a shift in emulsion morphology from w/o to o/w. The resulting transition from asphaltene- to NaN-controlled properties significantly limits oil−water phase separation as a result of an increase in the surface area to volume ratio of dispersed droplets and an enhancement of interfacial asphaltene partitioning. Contrary to NaN-free systems, it was also observed that both the temperature and solvent aromaticity have a minimal effect on the phase behavior of NaN formulations. Furthermore, undissociated naphthenic amphiphiles, referred to as naphthenic acids, are capable of promoting oil−water phase separation under acidic formulation conditions.
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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".