Mineral Chabazite for Bitumen Cracking and Upgrading
Bibliographic record
Abstract
The oilsands of North America may well represent the world’s largest available petroleum reserve. The oil or “bitumen” recovered is much more viscous than normal petroleum and must be diluted with expensive solvents before it can be transported by pipeline for chemical processing. The bitumen also typically contains an order of magnitude higher levels of contaminants (sulfur, nitrogen and heavy metals) than traditional crude. Economical catalysts for in-field processing would need to be single pass, disposable cracking agents which could improve the performance of visbreaking processes and enhance the economics of in-field upgrading. If the catalysts could concomitantly complex and remove S, N and/or metals, initial product quality could be substantially improved. Owing to unusual chemical and morphological properties, mineral zeolite chabazite was chosen for modification and testing. Commercial zeolite Y FCC catalyst was also evaluated. Sedimentary chabazite has a platy morphology composed of layers of submicron crystals in sheets. Its huge exterior surface area (90m2/g, 1/6 of the total surface area), is accessible to the large hydrocarbon molecules found in bitumen such as asphaltenes. Hchabazite has very high acid strength (retaining ammonia to nearly 550 °C, a full 100 °C higher than the commercial zeolite Y) allowing it to break large bitumen molecules. Under the mild cracking conditions tested (1 hour at 400 °C), catalyst-bearing oilsands samples produced toluene extractable products that showed significantly reduced boiling points, substantially more middle distillates and less resid. This effect was much more pronounced in the case of modified chabazite than for an equivalent addition of zeolite Y FCC catalyst. The addition of the modified chabazite drops the viscosity by a factor of 4 vs. typical visbreaking.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.002 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".