Managing the Risks Associated With Operating a Hydrotreater Reactor With Possible High-Temperature Hydrogen Attack Damage
Bibliographic record
Abstract
Abstract High-temperature hydrogen attack (HTHA) is a damage mechanism that can detrimentally affect the service life of carbon steel and low-chrome pressure equipment in the petroleum refining and related industries. HTHA involves the diffusion of hydrogen into steel, where it chemically reacts with free carbon at high temperatures to produce methane. This methane then gets trapped inside small cavities and other material defects. Over time, the rising methane pressure in these cavities can cause damage at the material grain boundaries. To this end, long-term exposure to high-temperature hydrogen environments can lead to volumetric damage that can diminish the load carrying capability of pressure equipment and accelerate the propagation of crack-like flaws. There have been several known industry failures attributed to HTHA damage as well. This paper summarizes a case study of a detailed analytical evaluation of potential HTHA damage in a vintage C-0.5Mo hydrotreater reactor. The goal of this study is to quantify the severity of HTHA damage using methods developed as part of an ongoing, multi-year Joint Industry Project (JIP) to justify continued operation of the reactor until the earliest practical replacement opportunity. HTHA damage and crack growth predictions are carried out based on documented historical operating conditions. Additionally, sensitivity in predicted remaining life to anticipated future operating temperatures is considered. Furthermore, based on state-of-the-art non-destructive examination (NDE) methods, fracture mechanics-based minimum pressurization temperature (MPT) envelopes are generated to help guide start-up and shut-down procedures that mitigate the risk for brittle fracture. Practical recommendations are also provided to facilitate the interpretation of NDE findings and to implement on-going failure mitigation and risk management strategies, including the development of Integrity Operating Windows (IOWs), for the reactor until planned replacement.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".