How is the sulfiding process monitored?

How is the sulfiding process monitored?

Modern refineries use online H₂S and hydrogen analyzers to monitor sulfiding progress. The process involves:

1. Drying and wetting the catalyst bed.
2. Gradually heating the reactor while introducing the sulfiding agent.
3. Tracking H₂S concentration in the effluent gas to detect breakthrough — the point at which the catalyst becomes fully sulfided.
4. Holding at a final temperature (typically 600–660°F) until completion.