Solvent–Coal–Mineral Interaction during Solvent Extraction of Coal
Bibliographic record
Abstract
Solvent extraction of coal is a coal-to-liquids conversion process whereby the organic matter in coal is dissolved in a solvent to produce a substantially mineral matter free product. The solvent extraction of Poplar lignite coal was studied with three model solvents (tetralin, quinoline, and 1-naphtol) and one industrial coal liquid derived solvent. Of interest was the fate of hydrogen, nitrogen, sulfur, and mineral constituents during physical dissolution at 200 °C and during reactive dissolution at 400 °C. The hydrogen redistribution in all solvents at 400 °C was within a narrow range, even though hydrogen-donor solvents resulted in higher extraction yield and in a higher H/C ratio of the residue. Quinoline strongly interacted with the coal, which masked its high physical extraction yield at 200 °C and enabled more mineral matter to be stabilized in solution. This behavior is typical of nitrogen bases in the coal, but was amplified by quinoline. Nitrogen redistribution took place with all solvents to nitrogen enrich the residue. Little or no sulfur redistribution took place during solvent extraction at 200 °C with any of the solvents, but at 400 °C, sulfur was redistributed. Evidence that sulfur is removed from the mineral matter during solvent extraction was provided by an observed decrease in S/Fe ratio, decrease in sulfur content of the ash, and increase in S/C ratio of extraction residues.
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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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".