Thermal Behavior of Potassium C<sub>1</sub>–C<sub>12</sub> <i>n</i>-Alkanoates and Its Relevance to Fischer–Tropsch
Bibliographic record
Abstract
Abstract The thermal behavior of potassium C1–C12n-alkanoates (K-carboxylates) were studied over the temperature range T/K = (243 to 873). A number of problems in industrial Fischer–Tropsch facilities were attributed to these compounds, but this study also revealed some beneficial effect that may directly be related to the thermal behavior of potassium methanoate. The unusually low melting point of potassium methanoate, T/K = (442.2 ± 0.3), combined with its thermal stability to T/K ≈ (693), may explain the ease of distribution of the potassium promoter of iron-based Fischer–Tropsch catalysts during synthesis even when potassium promoter is added separately. The C2–C12 K-carboxylates were all thermally stable at temperatures T/K ≤ (713), and significant mass loss was not observed at T/K ≤ (748). The thermal stability and high melting point of potassium propanoate, T/K = (636.9 ± 0.3) and potassium butanoate, T/K = (623.1 ± 0.3), in particular caused these compounds to be prone to cause pressure drop problems in refining units. The C4–C12 K-carboxylates melted to a liquid crystal phase first, before clearing at higher temperature. One or more solid–solid transitions were observed in all of the K-carboxylates, with the exception of potassium hexanoate.
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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 | 0.000 | 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) | 0.002 | 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 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".