LA Bucket Brigade : Refinery Accident Database

About the Database

Motiva Enterprises (2719), Convent

Causal Factor: Instrument Failure

LDEQ Accident Number Accident Date	Point Source(s)	Notes	Amount of Release
No LDEQ Reported 2007-04-08	HGU Torvex Incinerator (EPN 79J-904)	Cause: a temp. swing triggered a temperature alarm and an operator responded to the alarm by making adjustments to the operation of the unit Followup: No Notes: Motiva will incorporate control valve set point guidance into supporting documentation for operators to prevent swings in incinerator burner outlet temp. from triggering the low temp. alarm; Implement a troubleshooting guide to assist operators with operating the control valve when it is believed to be sticking.	Carbon Monoxide: 161.0 pounds Volatile Organic Compounds: 176.0 pounds Hydrogen Sulfide: 5.0 pounds Methanol: 176.0 pounds
110293 2008-10-22	Boiler 801 (81F-801)	Cause: Faulty level alarm on the C3/C4 H2S Absorber caused a heater to trip. This caused the amine circulation to be reduced which inadvertently caused overloading of the amine system. Followup: Yes Notes: Affirmative defense letter precedes regular report. Motiva will review potential threats for the instrumentation to determine appropriate modifications or adjustments	Sulfur Dioxide: 1,221.0 pounds
No LDEQ Reported 2008-09-23	Tail Gas Treating Unit 4 (78H-101)	Cause: failure of TGTU Absorber Tower level controller Followup: No Notes: Affirmative defense letter
107907 2008-08-10	Boiler 801 (81F-801) Boiler No 2 (31F-802)	Cause: loss of accurate level and flow info to the HGU's carbon recovery section resulted in a unit upset by the carrying of hydrocarbon material to the flare system for pressure relief Followup: No Notes: Motiva will review potential threats for the instrumentation to determine appropriate modifications or adjustments.	Sulfur Dioxide: 75,172.0 pounds Hydrogen Sulfide: 292.0 pounds
No LDEQ Reported 2008-05-02	Fluid Catalytic Cracking Unit Wet Gas Scrubber (EPN 2F-903)	Cause: malfunctioning FCCU WGS continuous emissions monitoring system analyzer Followup: No Notes: Affirmative defense letter.
116459 2009-07-14	flare	Cause: "H-Oil recycle compressor inadvertently tripped due to a false vibration indication, which forced the H-Oil Unity to depressure;" had to flare. No DEQ report in this file. RQs not exceeded. Followup: No Notes: No info given.
128236 2010-12-20	FLARE: Flare #3	Cause: A process upset occurred at the H-oil unit resulting in a flare ground fire. Approximately three barrels of heavy cycle gas oil and diesel fuel impacted the soil/grass which caught fire and burned the grass. Refinery follow-up report states that the incident was attributed to faulty instrumentation on the unit knock-out flare drum. FLARE. FIRE. Followup: Yes Notes: RQ. Refinery letter states that reportable quantities for oil and sulfur dioxide were exceeded. Connected to a citizens complaint that Flare #3 was on fire. Ascension Fire Department was on scene to extinguish the grass fire. Motiva made efforts to contain the sour hydrocarbon within the FGR system and to treat sour gas streams prior to depressuring to the flare system, However, sour gas was still combusted in the flare. Second time possibly exceeding the 500-pound limit of SO2 within two months due to system upset with the H-Oil unit: See incident report 127630.	Heavy Cycle Gas Oil: 130.0 gallons Sulfur Dioxide: 737.0 pounds
135985 2011-12-19	flare #2	Cause: The incident occurred at Motiva's Refinery on 12/19/11 due to an upset of the refinery's fluid catalytic cracking unit (FCCU). The upset began when the FCCU Wet Gas Compressor controller unexpectedly switched to back up and slowed the FCCU Wet Gas Compressor speed down. This over-pressured FCCU Fractionator tower which caused the tower's pressure controller to open the flare. The FCCU Wet Gas Compressor controller was taken out of automatic mode and placed into manual mode and the speed was increased to reduce the FCCU Fractionator tower pressure. The flaring ceased when the pressure reduced on the FCCU Fractionator. Followup: No Notes: No Information Given. Claims that they released 346lbs OVER the permitted limit but did not exceed 500 lbs. The value is greater than 346 lbs and less than 500 lbs.	Sulfur Dioxide: 346.0 pounds
130553 2011-04-11	flare #2	Cause: Incident occurred due to an upset of the refinery's fluid catalytic cracking unit (FCCU). The FCCU Wet Gas Compressor has three speed probes wired to the Triconex system, which performs the governor controls for the compressor's desired speed. The Triconex system processes the three speed readings and sends an electronic output signal (basically an average speed value of the three probe readings) to the CCC control system (which includes a 1st and 2nd stage antisurge controller). The CCC controller uses the speed signal to determine if the the compressor is "running" of "stopped". The upset began when the 1st Stage Wet Gas Compressor speed signal malfunctions sending a false reading to the compressor speed controller to decrease speed. The speed controller interpreted the low speed signal to mean the compressor was shutting down. To protect he compressor it fully opened the anti surge spillback creating a recycle from the compressor discharge to the suction. Since the low speed signal was false and the machine was not shutting down the recycle overloaded and the capacity of the Wet Gas Compressor and it could not keep up with the gas coming from the Main Fractionator. With the Wet Gas Compressor maxed out, the gas from the Main Fractionator Overhead could not get out and the pressure controller opened to the flare. The flaring ceased when the spillback valve was closed and the pressure reduced on the Main Fractionator. The flaring was a result of over pressuring of the Fractionator. The over pressure condition occurred due to the Wet Gas Compressor antisurge recycle valve going fully open due to a false low speed reading reading on the 1st stage anti surge controller. Followup: Yes Notes: Operations took immediate action to begin the process of stabilizing the FCCU by cutting back unit charge rate. Both the 1st and 2nd Stage Wet Gas Compressor speed controllers were set to from automatic to manual while E&I began troubleshooting the speed signals. Actions were taken to provide the operator an alarm in the event the condition reoccurs with instructions on how to mitigate until technical support arrives. All wiring associated with the CCC Control system was inspected on 4/11/11. Voltage checks were performed on all circuits and the speed signal was tested on 4/11/11. The CCC controllers will be replaced and the data recording software will be upgraded during the 2011 FCCU turnaround for a target completion date of 8/31/11. Flare # 4 exceeded maximum opacity limits during this incident.	Sulfur Dioxide: 3,585.5 pounds Hydrogen Sulfide: 7.0 pounds
149560 2013-07-10	wastewater sewer trench	Cause: On July 10, a release was reported at the Fluidized Catalytic Cracking Unit. The event was caused by a partially opened pump bleeder valve that released Heavy Straight Run (HSR), a gasoline component, directly into a process wastewater sewer drain. The drain overflowed and HSR pooled in an open sewer trench and was subject to evaporation losses to the air. Followup: No Notes: No remedial actions given. Incident initially reported as potential exceedance of 10 pound RQ for benzene. After further calculation, the total benzene emissions were not above RQ.
148806 2013-05-18	Flare #3	Cause: On the morning of May 18, the H-Oil Unit was operating normally when emergency pressure control valve 70HV234 inadvertently opened. Operations immediately reduced charge to the unit and closed the emergency pressure control valve in an attempt to re-engage operation, which was unsuccessful. In order to prevent an unsafe condition from the elevated temperatures and levels in equipment, operations stabilized the unit by flaring and removing charge from the unit to start a controlled shutdown. Followup: Yes Notes: Operations immediately reduced charge to the unit and closed the emergency pressure control valve in an attempt to re-engage operation, which was unsuccessful. In order to prevent an unsafe condition from the elevated temperatures and levels in equipment, operations stabilized the unit by flaring and removing charge from the unit to start a controlled shutdown. After investigation, it was concluded that the restriction orifice in the valve positioner relay plugged causing air pressure from the valve positioner to the actuator to drop below the pressure threshold required to hold the valve closed. The replacement of a control valve positioner, filter, and air regulator will eliminate the recurrence of an identical event in the short term. The replacement of this equipment will be conducted during the 2013 H-Oil reactor entry shutdown which is currently underway. Motiva will complete the proposed replacements prior to completion of the 2013 H-Oil reactor entry shutdown. To reduce the likelihood of a similar event from occurring in the future, Motiva will inspect these components during subsequent H-Oil reactor entry turnarounds for evidence of plugging and replace equipment as necessary. The total amount of hydrogen sulfide does not exceed the RQ of 100 pounds, but the maximum lb/hr emissions limit was exceeded for the hours between 8 AM and 11 AM. The permitted rates and amount released above authorized emissions were listed, but not the exact total amounts emitted.	Sulfur Dioxide: 28,884.0 pounds Hydrogen Sulfide: 50.3 pounds
156354 2014-05-28	H-Oil Unit pump 70P-102	Cause: Motiva's H-Oil unit lost indication on pump 70P-102 resulting in a unit cut-back and associated flaring. The incident was initially reported as a potential exceedance of the 500lb RQ for SO2, but subsequent calculations determined that the RQ was not exceeded. Both H2S and SO2 are thought to have escaped during this flare event. Followup: No Notes: Remediation not addressed. Report indicates that no one was injured or killed and no road closures occurred in connection with the incident.