Treating · Refining
Sulfur Recovery Unit
The plant that takes the hydrogen sulfide removed from fuels and gas and turns it into liquid elemental sulfur, using the Claus process.
What it does
A furnace burns part of the hydrogen sulfide, then catalytic stages convert the rest to sulfur. A tail gas unit cleans what is left so very little sulfur reaches the air.
Basics
| Feed | Acid gas from amine units and sour water strippers |
| Three stage Claus | About 98 to 99% recovery |
| With tail gas treating | About 99.9% recovery |
Common failures
- Unit trip that sends acid gas to the flare and raises sulfur dioxide emissions
Troubleshooting
- Symptom
- Recovery dropping
- Likely cause
- Wrong air to acid gas ratio in the furnace
- What to check
- Check the tail gas analyzer and adjust combustion air