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Shell Facility (3462), St. Rose

Causal Factor: Process Upset

LDEQ Accident Number
Accident Date
Point Source(s) Notes Amount of Release

Tank TK-8552
5-77 St. Rose Flare
Tank TK-8553
Cause: During a crude tank switch there was a unit upset when water and emulsion from a feed tank was introduced into the process, leading to the over pressuring of a de-salter vessel to the flare, a spill of water and emulsion to the water treatment facility and the shutdown of the compressor with additional flaring. During this unit upset tanks TK-8552 and TK-8553 roof legs inadvertently landed on the floor

Followup: No

Notes: Initial written report issued 6/20/07 but investigation revealed additional vent streams were routed to the flare so the numbers were updated on 8/14/07. To prevent this the water in the crude oil tank should have been drained prior to being placed in service. The crude tank was switched back to prevent further water and emulsion from being fed into the unit. Necessary steps were taken to clean up the wastewater treatment facility & return unit to normal. Tanks TK-8552 and TK-8553 were refilled to their normal levels. In the future, the water in the crude tank will be drained before the tank is placed into service
Xylene: 101.0 
Toluene: 110.0 pounds
Hydrogen Sulfide: 101.0 pounds
Ethylbenzene: 1,000.0 pounds
Hexane: 5,027.0 pounds
Benzene: 18.0 pounds
Sulfur Dioxide: 513.0 pounds
Volatile Organic Compounds: 5,686.0 pounds
Particulate Matter: 5,019.0 pounds
Nitrogen Oxide: 112.0 pounds
Carbon Monoxide: 5,558.0 pounds
No LDEQ Reported

5-77 (St. Rose Flare)
Cause: Loss of steam pressure when a tube failed in the boiler resulting in flaring

Followup: No

Notes: The boiler tube failure could not be predicted. Shut the process unit down until boiler repairs could be completed. The incident will be investigated and appropriate corrective actions will be implemented to prevent reoccurrence
Carbon Monoxide: 585.0 pounds
Hexane: 0.8 pounds
Nitrogen Oxide: 107.0 pounds
Particulate Matter: 20.0 pounds
Sulfur Dioxide: 75.0 pounds
Volatile Organic Compounds: 386.0 pounds
No LDEQ Reported

5-77 (St. Rose Flare)
Cause: A bearing failed on the vent gas compressor for the vacuum unit.

Followup: No

Notes: The bearing failure was not predictiable. The compressor was shut down and a valve to the St. Rose flare was opened to lower and control the seal drum pressure. The compressor was replaced with a spare and the unit was returned to normal operating conditions. The spare will be replaced with the repaired compressor during the next unit outage
Carbon Monoxide: 8.1 pounds
Hexane: 0.0 pounds
Nitrogen Oxide: 1.5 pounds
Particulate Matter: 0.3 pounds
Sulfur Dioxide: 4.2 pounds
Volatile Organic Compounds: 4.7 pounds