|Home||Search||Emissions||Pollutants||About the Database|
|State Police #||11-01678|
|Pollutant||Duration||Point Source||Greenhouse Gas||Criteria Pollutant||Ozone forming chemical||Amount of Release|
|Sulfur Dioxide||2 h 45 m||3700 SRU Malfunction||NO||YES||NO||1,573.0 pounds|
Accident Classified As: Reportable Quantity
The sulfur dioxide levels at the 3700 Thermal Oxidizer (EQT 0195) were intermittently elevated from approximately 3/24/11 from 8:40 am until 11:30 am. Valero estimates that the reportable quantity for sulfur dioxide was exceeded at 9:25 am. This event was attributed to a miscommunication between night and day-shift operators, as well as process pressure controller that needed calibration (tuning).
This upset was preventable.
Operators moved quickly to make manual control over automatic control valves that may have contributed to this event. Operational moves were conducted on a separate sulfur recover plant to help stabilize the upset. The following measures have been identified to help prevent recurrence:(1) Tune pressure controller for amine acid gas header to 3700 SRU (2) Communicate incident and reinforce the use of shift notes when communicating important details