Kinetic Models for Upgrading Athabasca Bitumen Using Unsupported NiWMo Catalysts at Low Severity Conditions
Bibliographic record
Abstract
Typically, the catalytic upgrading of heavy fractions (VGO and VR) has been studied using mostly conventional supported catalysts at temperatures and pressures higher than 400 °C and 6 MPa, respectively. This work focuses on the upgrading of heavy oils at much lower severity conditions using dispersed NiWMo catalysts for processing whole oil with no fractionation. A kinetic study was developed to determine parameters from experimental data obtained at temperatures of 320–380 °C and reaction times from 3 to 70 h at a total hydrogen pressure of 3.45 MPa and a stirring speed of 500 rpm in a batch reactor. The conversion, estimated as the reduction of the residue 545 °C + fraction, was fitted for a first-order reaction with an apparent activation energy of 200 kJ mol –1 . Two kinetic models are proposed to predict the conversion of the residue fraction and its product distribution. Comparison between experimental data and predictions using the proposed models exhibited good agreement with average absolute errors lower than 5%.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".