LA Bucket Brigade : Refinery Accident Database

About the Database

Shell Chemical East (26336), Norco

Releases of NOx

LDEQ Accident Number Accident Date	Point Source(s)	Notes	Amount of Release
152357 2013-11-13	GO-1 Elevated Flare (EPN 1-90)	Cause: On November 13, 2013, GO-1 had an unexpected process upset which resulted in flaring at the GO-1 Elevated Flare. The flaring was a result of the GO-1 South Acetylene Converter going off specification due to contaminants in the hydrogen supply to the converter due to a valve misalignment at Motiva's S3 Sulfur Unit. The material was flared at the GO-1 Elevated Flare to prevent additional upsets in GO-1. Incident Investigation is ongoing. Shell will provide an update within 60 days. Report states that no reportable quantities were exceeded. Followup: Yes Notes: GO-1 operations took corrective actions to return the acetylene converters to normal operation. GO-1 added steam and hydrogen to both converters. A pressure control valve for import hydrogen was put in manual to correct variations in the flow to the converters. The PSA hydrogen was stopped to the converters as part of initial troubleshooting, but was later lined up after the valve misalignment was discovered and corrected. Once the acetylene converters were returned to normal operating conditions the flaring stopped. To prevent this incident from reoccurring, the operations specialist at S3 has updated piping and instrument drawings to clarify the location of the S3 hydrogen and nitrogen valves in the field. Also the operations specialist at S3 has car sealed close the hydrogen valve from S3 to GO1.	366.1 pounds
152132 2013-11-03	OL-5 Ground Flare (EPN 7-84) and OL-5 Elevated Flare (EPN 6-84) OL-5 Ground Flare and Elevated Flare	Cause: On November 3, 2013, OL-5 had an unexpected process upset which resulted in flaring at the OL-5 Ground Flare (EPN 7-84) and OL-5 Elevated Flare (EPN 6-84). The flaring resulted from OL-5 taking a stream into the unit from OP-1 which caused the Acetylene Converter to go off specification. The material was flared at the OL-5 Ground Flare and OL-5 Elevated Flare to prevent additional upsets in OL-5. Followup: Yes Notes: Once OL-5 Operations was aware that the acetylene content increased above specification in the outlet of the acetylene converters, OL-5 Operations followed normal procedure and diverted the acetylene converter effluent to the OL-5 flare system until the Acetylene converter effluent was back in specification. The material was flared to prevent additional upsets in the unit. OL-5 operations immediately stopped the OP-1 de-ethanizer tops flow into the unit and ethylene product flow to the pipeline. The ethylene splitter received some of the high acetylene process gas exiting the acetylene converters. The ethylene splitter overhead and the liquid in the ethylene splitter reflux drum were sent to the flare until the column was also back on specification. Once the ethylene product stream was back on specification, the ethylene product leaving the ethylene splitter was returned to the pipeline and the flaring stopped. Report states that all released materials were dispersed naturally in the atmosphere from the OL-5 Ground and OL-5 Elevated flare stacks. Currently, an investigation is occurring. The results from this investigation will be incorporated, where applicable, into the standard work processes at the OL-5 Unit to prevent recurrence. Shell Chemical confirmed that the reportable quantity for Highly Reactive Organic Compounds was exceeded. The maximum permitted limits were exceeded for carbon monoxide, nitrogen oxide, particulate matter, and volatile organic compounds.	1,050.0 pounds
150789 2013-08-31	7-84 (OL-5 Ground Flare, 6-84 (OL-5 Elevated Flare, FE-101)	Cause: On the morning of August 31, 2013, Shell Chemical's OL-5 Process Unit experienced a higher than normal level of carbon monoxide (CO) in the furnace feed. The additional unexpected CO in the feed came from Enterprise, a supplier of feed to OL-5, and as a result of recent decoking activities. The higher level of CO was initially consumed by the Product Hydrogen and Converter Hydrogen Methanators, however, this did not resolve the issue. Without taking action, continued high levels of CO would have led to the ethylene product going off specification which in turn would have led to substantial additional flaring. Therefore, as per normal operating procedures, OL-5 opearations began routing the high AC converter stream to the flare to lower the CO levels in the process in an effort to prevent a further, more severe, upset in the OL-5 Process Unit. Once the AC converter effluent was within specifications, it was routed back to normal operation. Followup: Yes Notes: To minimize impacts, OL-5 operations adjusted unit operations in order to consume the excess CO in the Product Hydrogen and Converter Methanators. Once the Product Hydrogen and Converter Hydrogen Methantators became overwhelmed, OL-5 operations immediately diverted the AC converter effluent to the OL-5 flare system. Operations then used a different source of hydrogen that did not contain elevated carbon monoxide. Once the AC converter effluent was within specifications OL-5 operations positioned the stream back to its normal routing, eliminating flaring. An investigation is occurring. The results will be incorporated, where applicable, into the standard work processes at the OL-5 unit to prevent recurrence. Shell Chemical confirmed that reportable quantities for carbon monoxide, nitrogen oxide, and High Volatile Organic Compounds were exceeded. In addition, the maximum permitted limits were exceeded for carbon monoxide, nitrogen oxide, particulate matter, and volatile organic compounds at the OL-5 elevated flare. Shell admitted that Carbon Monoxide exceeded RQ for August 31, but not Sept 1. Carbon Monoxide exceeded RQ on both dates. Similarly, VOCS exceeded RQ for both Aug 31 and Sept 1, but was only reported as exceeding for the first. VOCs are mislabeled as HRVOCs (highly reactive VOCs).	2,701.1 pounds