A Fluid Catalytic Cracking (FCC) unit turns heavy hydrocarbon residue into gasoline. The riser runs at 520 C, the regenerator at 720 C and 4-5 bar. The Texas City 2005 blast killed 15. NFPA 30, API 2510 and API RP 752 cover FCC fire protection.
FCC Process
- Feed: VGO 350 C
- Catalyst: Zeolite 5-100 micron
- Riser: 520 C, 2-3 s contact
- Regenerator: 720 C cat combustion
- Capacity: 40,000-100,000 bpd
Riser and Catalyst Risk
- Erosion: Catalyst wears metal
- Feed pipe hot spot: 750 C
- Expander: Flue gas 720 C turbine
- Slurry pump: Seal fire
- Hot rotating: Steam curtain
Water Spray NFPA 15
- Vessel exposure: 10.2 L/min/m2
- Riser: 20.4 L/min/m2 special
- Structural steel: 4.1 L/min/m2 column
- Monitor nozzle: 20 L/s 45 m range
- Duration: 4 hours
Texas City 2005 Lessons
- Incident: Isomerization unit overfill
- Dead: 15, injured 180
- Cause: Trailer siting
- CSB report: Safety culture
- MOC: Management of Change mandatory
Turkish Refinery FCC
- Tupras Izmir Aliaga: FCC 40,000 bpd
- Tupras Kirikkale: Unit 2
- STAR Aliaga: SOCAR 2018
- BYKHY Annex-12: Petrochemical
- SEVESO III: Upper-tier
FCC with SprinkCalc
SprinkCalc sizes FCC riser water-spray 20.4 L/min/m2, monitor nozzle 20 L/s, structural 4.1 L/min/m2 and NFPA 30 / API 752 check.
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Sources & Further Reading
NFPA 30, NFPA 15, API 2510, API RP 752, CSB Texas City. NFPA 30 Flammable and Combustible Liquids.