Oil Shale Pyrolysis: Conversion Dependence of Kinetic Parameters
Bibliographic record
Abstract
Oil can be recovered from kerogen in oil shale by pyrolysis. The devolatilization kinetics of the pyrolysis of oil shale from the Irati Formation in Brazil was studied. Kinetic parameters were determined from dynamic thermogravimetric analysis over the temperature range 323–1173 K, using different model-free methods. Evaluation and validation were performed by pyrolysis at 673 K for 3 hours. It was found that the activation energy depended on the extent of conversion. Activation energy increased over the range 215–255 kJ/mol for conversion in the range 0.15 ≤ α ≤ 0.55, where α = 1 for pyrolysis at 1173 K. When the reaction rate was high, the conversion calculated using kinetic parameters derived by the Friedman method was more accurate than those calculated from the Flynn–Wall–Ozawa and the Kissinger–Akahira–Sunose methods. The latter two methods performed better when the reaction rate was lower, i.e., at higher conversion. Isothermal kerogen pyrolysis approached an incomplete conversion limit that could be increased only by increasing the temperature; this type of behavior was predicted by the conversion dependence of activation energy. The observed activation energy is an average of the different activation energies of the individual compounds in kerogen. As conversion progresses, the compounds with lower activation energies are more readily converted, so that the average activation energy of the compounds that remain increases with increasing conversion. The work highlighted the importance of employing conversion-dependent kinetic parameters when modeling oil shale pyrolysis for process design, especially when the process is designed for high kerogen conversion.
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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 | 0.001 | 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".