Study of Carbon Formed on Stainless Steel 304H in a Simulated Environment of the Convection Section of the Ethane Cracking Furnace System
Bibliographic record
Abstract
The stainless steel 304H (SS304H) is one of the important alloys used in petrochemical industry, such as in the convection section of the ethylene production furnaces. The exposure to carburizing gases makes this alloy susceptible to carbon formation and potential carburization. The present study focuses on understanding the coking behavior of SS304H in ethane/steam environment and the effect of H2S at 700oC. Long-term (90 hours) experiments in such environment show that the addition of ppm amounts of H2S has a pronounced effect on the morphology of the carbon formed on the SS304H surface, as shown by scanning electron microscopy. In the absence of H2S, the deposited carbon forms distinct fibers, which are distributed homogeneously on the surface. The addition of 15 ppm H2S results in the formation of carbon clusters, consisting of very thin fibers that are tightly entangled. Also, experiments in the presence of H2S showed a systematic decrease in the amount of carbon as H2S increased from 1 to 2, 5, 7, and 10 ppm. At 10 ppm H2S, no carbon was observed on the SS304H surface after 4 h of exposure to ethane/steam at 700oC. Mass spectrometry studies showed that the addition of H2S does not affect the temperature or products of ethane cracking. The effect of the SS304H coupons on the ethane cracking products was also studied by mass spectrometry, and showed that the ethane cracking process is not significantly affected by the presence of the metal coupon.
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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 | 0.001 | 0.000 |
| 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".