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Marathon Ashland Petroleum (3165), Garyville

LDEQ Accident Report

Accident #157090
PDF AvailablePDF
State Police #14-02857
Accident Date2014-06-27
Report Date 2014-07-02
Follow-up Date 2014-08-26
Follow-up: Yes

Pollutants Released

Pollutant Duration Point Source Greenhouse Gas Criteria Pollutant Ozone forming chemical Amount of Release
Sulfur Dioxide216hUnit 25 FCCU wet gas compressor shutdownNOYESNO8,994.0 pounds
Highly Reactive Volatile Organic Compounds216hUnit 25 FCCU wet gas compressor shutdownNONOYES246.0 pounds
Methane216hUnit 25 FCCU wet gas compressor shutdownYESNOYES415.8 pounds
Ethane216hUnit 25 FCCU wet gas compressor shutdownNONOYES112.1 pounds
Ethylene216hUnit 25 FCCU wet gas compressor shutdownNONOYES5.3 pounds
Acetylene216hUnit 25 FCCU wet gas compressor shutdownNONONO0.3 pounds
Propane216hUnit 25 FCCU wet gas compressor shutdownNONOYES397.7 pounds
Propylene216hUnit 25 FCCU wet gas compressor shutdownNONOYES84.7 pounds
n-Butane216hUnit 25 FCCU wet gas compressor shutdownNONONO807.2 pounds
Isobutane216hUnit 25 FCCU wet gas compressor shutdownNONOYES324.0 pounds
Butene216hUnit 25 FCCU wet gas compressor shutdownNONOYES193.6 pounds
Pentene Plus216hUnit 25 FCCU wet gas compressor shutdownNONONO719.8 pounds
Carbon Dioxide216hUnit 25 FCCU wet gas compressor shutdownYESNONO2,158.5 pounds
Carbon Monoxide216hUnit 25 FCCU wet gas compressor shutdownNOYESNO171.5 pounds
Hydrogen216hUnit 25 FCCU wet gas compressor shutdownNONONO50.2 pounds
Nitrogen216hUnit 25 FCCU wet gas compressor shutdownNONONO105,957.5 pounds
Hydrogen Sulfide216hUnit 25 FCCU wet gas compressor shutdownNONONO10.6 pounds
NOx216hUnit 25 FCCU wet gas compressor shutdownNONOYES669.9 pounds
Particulate Matter 10216hUnit 25 FCCU wet gas compressor shutdownNOYESNO266.0 pounds
Particulate Matter 2.5216hUnit 25 FCCU wet gas compressor shutdownNOYESNO266.0 pounds
Methane216hUnit 25 FCCU wet gas compressor shutdownYESNOYES415.8 pounds
Ethane216hUnit 25 FCCU wet gas compressor shutdownNONOYES112.1 pounds
Ethylene216hUnit 25 FCCU wet gas compressor shutdownNONOYES5.3 pounds
Acetylene216hUnit 25 FCCU wet gas compressor shutdownNONONO0.3 pounds
Propane216hUnit 25 FCCU wet gas compressor shutdownNONOYES397.7 pounds
Propylene216hUnit 25 FCCU wet gas compressor shutdownNONOYES84.7 pounds
n-Butane216hUnit 25 FCCU wet gas compressor shutdownNONONO807.2 pounds
Isobutane216hUnit 25 FCCU wet gas compressor shutdownNONOYES324.0 pounds
Butene216hUnit 25 FCCU wet gas compressor shutdownNONOYES193.6 pounds
Pentene Plus216hUnit 25 FCCU wet gas compressor shutdownNONONO719.8 pounds
Carbon Dioxide216hUnit 25 FCCU wet gas compressor shutdownYESNONO2,158.5 pounds
Carbon Monoxide216hUnit 25 FCCU wet gas compressor shutdownNOYESNO171.5 pounds
Hydrogen216hUnit 25 FCCU wet gas compressor shutdownNONONO50.2 pounds
Nitrogen216hUnit 25 FCCU wet gas compressor shutdownNONONO105,957.5 pounds
Hydrogen Sulfide216hUnit 25 FCCU wet gas compressor shutdownNONONO10.6 pounds
NOx216hUnit 25 FCCU wet gas compressor shutdownNONOYES669.9 pounds
Particulate Matter 10216hUnit 25 FCCU wet gas compressor shutdownNOYESNO266.0 pounds
Particulate Matter 2.5216hUnit 25 FCCU wet gas compressor shutdownNOYESNO266.0 pounds

Accident Classified As: Reportable Quantity

Cause of Problem: Equipment Failure

The wet gas compressor (WGC) suction flow and discharge pressure dropped suddenly, causing the WGC spillback valve to open 100%. The fractionator overhead pressure increased when the WGC spillback opened up. The high fractionator pressure SIS trip point was reached (36 psi), which tripped the unit. Fuel gas was routed to the fractionator overhead accumulator, which was being vented to the flare to keep pressure on the reactor to prevent O2 from the regen from backing into the reactor. No offsite impacts were observed by the air monitoring team. The reportable quantities for Sulfur Dioxide, HRVOCs and VOCs were exceeded. Update: cooling coil in Alkyl Unit Vent Gas Absorber (27-1107) failed.

Discharge Preventable - Yes

The root causes were identified as NO Procedure/Preventative Maintenance for Equipment Needs Improvement.

Notes/Remedial Actions

The SIS system reacted as designed to shutdown the FCCU due to the opening of the compressor spillback valve. An incident investigation will result in recommendation items designed to prevent recurrence of this event. Update: The root causes were identified as 1) cooling coil in Alkyl Unit Vent Gas Absorber (27-1107) failed. Cause of failure is unknown. Root Cause #1: Cannot be determined until the Alkyl Unit Shutdown. Recommendation: Inspect the cooling coil in the Alkyl Unit Vent Gas Absorber (27-1107) and determine cause of failure. Based on the cause of failure, recommendations will be generated to prevent recurrence. [Complete by December 15, 2016] 2) Quaterly PMs on cooling coil in Alkyl Vent Gas Absorber failed to identify the coil was leaking. Root Cause #1: No Procedure. Recommendations: Create Operations procedure for performing the quarterly leak testing on the cooling coil in the alkyl Vent Gas Absorber. Include a step that requires operators to verify proper documentation of test result in PM work order closure. [Complete by November 18, 2014]. Root Cause #2 Preventive/Predictive Maintenance Needs Improvement. Indetify flouride sample locations for discovering a leak in Alkyl Vent Gas Absorber cooling coil [Complete by November 18, 2014].