Conversion · Refining
Fluid Catalytic Cracker
A unit where hot gas oil meets a powdered catalyst in a riser and cracks into gasoline, light olefins and other lighter products.
What it does
The catalyst circulates between the reactor and a regenerator that burns off the coke laid down during cracking. It is a main gasoline maker in many refineries and feeds the alkylation unit.
Basics
| Feed | Vacuum gas oil |
| Riser | About 480 to 540 °C (900 to 1,000 °F), 10 to 30 psi |
| Catalyst | Fine powder, regenerated continuously |
| Products | Gasoline, light cycle oil, olefins, gas |
Common failures
- Catalyst carried over with the product vapours when the reactor cyclones do not separate it
Troubleshooting
- Symptom
- Catalyst fines in the heavy product
- Likely cause
- Reactor cyclones not separating well
- What to check
- Check fines in the bottoms and inspect the cyclones at the next shutdown