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Motiva Enterprises (1406), Norco

Releases of n-Butane

LDEQ Accident Number
Accident Date		 Point Source(s) Notes Amount of Release
134290

2011-09-29		Coker Flare FE-401
Cause: While starting the Coker Jet Pump on 9/29/11 at 6:45pm, the electrical breaker at Motiva's Coking Unit tripped de-energizing the Motor Control Center. Consequently, the Coker Wet Gas Compressor tripped offline therefore resulting in unit flaring and operating in hot circulation mode. Hot circulation mode is an operating mode in which the unit recycles feed at high temperatures. This mode of operation lessens the amount of flaring in comparison to a complete unit shutdown. The initial inspection of the Jet Pump revealed that the auto-transformer serving as a soft start for this pump had failed causing the electrical breaker to trip open. Once repairs were completed, the Coker Unit was safely re-started and flaring stopped.

Followup: No

Notes: Immediately, Operations placed the furnace F-125 in hot steam standby and brought the Coker Unit into hot circulation mode to prevent additional flaring of non treated gas. Norco maintenance personnel were called out to troubleshoot the trip of the Coker Wet Gas Compressor and related equipment. The auto-transformer was removed from the circuit. Relay coordination was modified in order to protect the new circuit. After troubleshooting, maintenance personnel determined that operations could safely re-start the Coker Process Unit. During this time the Coker Wet Gas Compressor was restarted and flaring stopped. By 12/31/11 a study will be completed to determine whether the auto-transformer can be permanently removed from the system. After this study is completed, a strategy will be created to address the required changes. This action will be completed by 3/31/12. Calculations confirm that the reportable quantity for sulfur dioxide was exceeded as well as the permitted maximum pound per hour emission limits for carbon monoxide, nitrogen oxide, particulate matter, sulfur dioxide, VOC's, 1,3 butadiene, and benzene as a result of the release.		5.4 pounds
156452

2014-06-01		charge pump, Hydrocracking Unit
Cause: Motiva's Hydrocracking Unit (HCU) flared process gas at the HCU Elevated Flare (FE 301) due to the partial shutdown of the HCU. A seal leak was discovered on the charge pump on the second stage of the HCU. Due to the location of the leak, the unit had to partially shut down to complete repairs. Flaring of hydrogen will continue intermittently to stabilize the remaining operating equipment. Flaring ceased once the charge pump was repaired and the unit returned to stable operating conditions. Flaring occurred on June 1 (367 minutes) and June 7 (1069 minutes).

Followup: Yes

Notes: After the unit was shut down and secured, maintenance and engineering investigated and identified that a seal failure occurred. A repair plan was promptly developed and executed. Due to this incident being a repeat issue in a short period of time, Motiva chartered a full investigation. Findings from this investigation resulted in the installation of additional check valves to control pressure swings and to help manage the integrity of pump seals.		27.1 pounds
154210

2014-02-27		RCCU
Cause: On 2/27/2014, an unexpected leak occured on Motiva's Residual Catalytic Cracking Unit (RCCU) second cyclone dip leg. Due to the location of the leak, the catalyst leak cound not be safely repaired while the unit was fully operations. A partial shutdown of the RCCU was conducted to stop the leak and complete repairs. While the unit was partially shut down, flaring occured intermittently at the RCCU Elevated Flare (EPN FE201) to safely stabilize equipment that was still operational. During the start up of RCCU, untreated dry gas was flared at the GO1 Elevated Flare.

Followup: Yes

Notes: To minimize additional unit upset and to safely repair the catalyst leak , the RCCU Unit was partially shut down in a safe manner. The catalyst leak was stopped and the second cyclone dip leg was repaired. The original report and the first follow up report included in the event description that untreated dry gas was flared at the GO1 Elevated Flare during the start-up of RCCU. This was not included in the final follow up report. Additionally, two follow up reports were sent by Motiva, the first dated 4/24/2014 to provide a 60 day follow up. In this correspondence it is stated that they will provide a second update within 60 days, as data gathering and investigation was ongoing. The final follow up report was received on 6/24/2014.		26.0 pounds
153484

2014-01-23		Elevated Flare (FE-201)
Cause: Motiva's RCCU Unit had a relief Valve (RV) on its Debutanizer Column lift and relieve to atmosphere. The RV lifted as its designed pressure setting after a pressure transmitter failed in the unit causing a pressure control valve to fail into closed position. Once this valve did not move to open position, the pressure within the Debutanizer Column built up and over pressured causing the RV to relieve as designed. To help relieve the pressure in the debutanizer column and to stop the RV from relieving the material was routed to the flare. Isobutane, Isobutene, N-Butane, Propane, and Propylene were potentially released from Motiva's Residual Catalytic Cracking Unit's (RCCU) Elevated Flare (FE-201).

Followup: No

Notes: Data gathering to perform calculations and investigation are ongoing. Shell will provide and update within 60 days as required by LAC 33:1:3925.A.3.