Ammonia Pyrolysis and Oxidation in the Claus Furnace
Bibliographic record
Abstract
The modified Claus process is commonly used in oil refining and gas processing to recover sulfur and destroy contaminants formed in upstream processing. In oil refining, in addition to the typical modified Claus plant feed of H 2 S and CO 2, NH 3 is also often present. NH 3 is a process contaminant and must be destroyed in the front-end furnace of the modified Claus plant, otherwise, it poses a risk of poisoning the catalyst beds and plugging off downstream equipment because of the formation of ammonium salts. In this paper, the pyrolysis and oxidation of NH 3 was studied under Claus furnace temperatures and residence times. Experimental data was taken, and new reaction rate expressions were developed for NH 3 pyrolysis and oxidation. The derived rate expressions are outlined as follows: the NH 3 pyrolysis rate expression r = A exp(− E a / RT ) P NH 3 1.25, where A is 0.00421 mol s - 1 atm - 1.25 cm - 3 and E a is 16.5 kcal mol - 1, and the NH 3 oxidation rate expression r = A exp(− E a / RT ) P NH 3 P O 2 0.75, where A is 4430 mol s - 1 atm - 1.75 cm - 3 and E a is 40.0 kcal mol - 1 . The rate expression for NH 3 pyrolysis matched experimental data within 13% and matched well with published data. The rate expression for NH 3 oxidation matched experimental data within 10%.
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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) | 0.000 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".