How is the sulfiding process monitored?
Modern refineries use online H₂S and hydrogen analyzers to monitor sulfiding progress. The process involves:
- Drying and wetting the catalyst bed.
- Gradually heating the reactor while introducing the sulfiding agent.
- Tracking H₂S concentration in the effluent gas to detect breakthrough — the point at which the catalyst becomes fully sulfided.
- Holding at a final temperature (typically 600–660°F) until completion.