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ExxonMobil Chemical Plant (286), Baton Rouge

Releases of Isoprene

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

Product line from Isopropyl alcohol unit
Cause: A product line from the isopropyl alcohol unit in the chemical plant was leaking. Vapors were being released to the atmosphere.

Followup: No

Notes: ExxonMobil located the leak. They were trying to determine what options they had to stop the leak. Amount of chemicals released is unknown.

Storage tank
Cause: The cause of the release was pressure in the feed tanks at the Waste water improvement unit.

Followup: No

Notes: A storage tank vented for 16 m. The cause of the release was pressure in the feed tanks at the waste water improvement (WILA) unit exceeded the vacuum vent setting for 14 m. The light material entered the flare knock out drum at the Olefins unit through a safety valve bypass which was left open inadvertently during the start up after Gustav. Manual error is the root cause. LDEQ said they would take this up at the next inspection. Exxon's written report was received on 10/6/08.
100.0 pounds


H furnace
Cause: Three events occurred within 24 hours of one another at the ExxonMobil Baton Rouge Chemical Plant. Two are reported in this report (LDEQ #107433), the other is reported separately (LDEQ #107421). In this incident (107433), a furnace tube leaked into convection section of H-furnace and caught fire. The tube leak occurred as a result of the incident described in report #107421. At approximately 5:56 PM on July 21, 2008, the charge gas compressor at the Olefins unit shut down when several processing cards in the gas turbine control system failed. When the compressor shut down, four furnaces automatically shut down and the gas in the furnaces was evacuated to the flare system. One of the remaining three furnaces was subsequently shut down while the remaining two furnaces continued to operated at 50% rates in order to maintain stable unit operations, which resulted in additional flaring for the duration of the event. The high rate of gas to the flare system resulted in the #25 flare smoking for 2 hours and 17 minutes. When the Olefins unit shut down, steam was introduced into the furnaces to displace the hydrocarbon feed to reduce flaring emissions. At 12:20 PM on July 22, 2008, while the H furnace was in the process of starting up, a leak was discovered in the convection section of the furnace. To stop the leak, water was introduced into the leaking pass of the furnace to displace the hydrocarbon feed. It is believed that the leak developed when steam was introduced into the furnace. Tube leaked into convection section of H-furnace and caught fire.

Followup: Yes

Notes: This incident is the result of the incident #107421 (see comments under that incident). Immediately after the incident began, five of the seven furnaces at the Olefins unit were shut down. Excess gas was sent to flare system. Water was introduced into the leaking furnace pass to displace the feed and prevent uncombusted hydrocarbons from leaking into the atmosphere. Concerning subsequent preventative actions, the failed processing cards were replaced. The H furnace was taken out of service to be inspected for leak location and repairs will be completed as necessary. Used water in the tube to eliminate the burning material. Flammable gass consisted of mainly Butane.

SACC unit LTO1
Cause: A leak developed in a fifty four inch overhead pipe at the SACC Unit LT01.

Followup: No

Notes: There is approximately 5 lbs per square inch (psi) or pressure on the pipe. The insulation of the pipe was removed to identify the source. Pictures included of the plug of the pipeline due to the hole and a view of the repaired line. On the incident report form it says that the initial report said that RQs might be exceeded, but that none were exceeded.

control valve of HCE compressor
WILA tanks #8 and 9
Cause: The release was caused by the failure of a control valve downstream of the HCE compressor. The control valve downstream of the HCE compressor failed to close which caused the HCE compressor to trip off.


Notes: Since there was no outlet for the vapor in the HCE system, the pressure built in the tanks until the pressure vents lifted, released hydrocarbon to the atmosphere. The back up hydrocarbon emissions control system which uses vacuum jets to recover the excess vapors was comissioned. Proper operation of the vacuum jets was confirmed shortly thereafter. The control valve and instrumentation will be repaired and inspected before being returned to servvice.
0.1 pounds

EPLA-W Compressor, flares #10, 25, and 26
Flares #10, 25, and 26
Cause: A fire resulted in a compressor shut down and material being flared from 10:30 pm - 11 pm. Around 10:30 pm the charge gas compressor (EPLA-W compressor) for the Olefins Maintrain furnaces tripped due to failed overspeed wiring. This occurred because of a small leak of lube oil from the steam driver which caught fire. This fire was small but close to the wiring which malfunctioned.

Followup: No

Notes: This incident is linked to incident #112824. The effluent gases were diverted to flares before the compressor could be repaired. Start up began around 8:45 pm on 2/18/09. Flaring during shut down through start up resulted in exceedances of RQs for ethylene, propylene, butadiene, nitric oxide, and sulfur dioxide. Also they had three compliance excursions from smoking of flares #10, #25, and #26. This was a non preventable incident from a malfunction. They are looking into preventing lube oil leaking and collecting near compressor wiring.
21.0 pounds

compressor KC-01
Cause: A combination release occurred due to a cracked pipe in the thermo well of the ethylene production unit.

Followup: Yes

Notes: An engineered clamp is being fabricated and will be installed to isolate the leak. Estimated 72 hours to install clamp and secure leak. Individually this event did not exceed the RQ for HRVOC, but in combination with another incident (#11-07037) the RQ for HRVOC was exceeded on Friday, November 11. Approximately 122 pounds of HRVOC's were released. On November 11, 2011 at approximately 13:51 Derek Reese stated the ongoing release subsided to 4.25 lbs/hr and was now below RQ. (still ongoing on report date 11/16/11) Area monitoring and LDEQ monitoring on the fenceline (including grab sample) did not detect anything. LDEQ did pick up .25ppb of Benzene. A total of 108 pounds per day of charge gas is being released as a result of this event. Cumulative emissions which include the total emissions from the incident and complete response, will be included in the follow-up report.
38.0 pounds

Flare gas system
Cause: A failure of the fuel gas control valve servomechanism actuator failed due to particulate matter in the hydraulic system, causing OLA-2X gas turbine to trip and material to be released to the Site's flare gas system.

Followup: Yes

Notes: Feed was removed from five of seven furnaces and the remaining two furnaces were operating at minimal rates in order to reduce the load on the flare system and emissions to the atmosphere. The hydraulic oil filters and servos were replaced upon discovery of the foulant. The hydraulic oil system was drained, cleaned, and charged with fresh oil in December 2012 to remove a suspected contaminate and particulates. ExxonMobil is conducting additional laboratory analysis of the lube oil at our lubes and specialities lab to determine if additional steps are needed to help prevent recurrence. In addition, improved filtration has been installed. A citizen complaint was recorded and given LDEQ incident number 144543. The complaint cites "Exxon release causing terrible odors, making the caller sick." The LDEQ report references this report, incident 144539 for information on the release. The reportable quantities for VOC, benzene, ethylene, propylene, isoprene, 1,3-butadiene, sulfur dioxide, and nitrogen oxide were exceeded as a result of this event.
399.0 pounds

Tank 21 and Rain Basin 1
Cause: A failed bleeder plug was found at Tank 801 in the BRCP's Aromatics Tankfield. Approximately 411 barrels of steam cracked naptha reached the sewer system via this bleeder. All material was retained in waste water treatment facility. While the naphtha was being pumped to tanks #778, #26, #22 and #21, a rain event occurred, which overwhelmed the facility's ability to pump the liquid to the tanks. Therefore, the material was diverted to the Rain Basin I surface impoundment. Of the water pumped into the basin, there were 1,712 lbs of benzene and 419 lbs of toluene.

Followup: Yes

Notes: The water was to be pumped to the waste water treatment plant for treatment before being discharged to outfall 001. Firefighting foam was placed on top to reduce volatilized chemicals. Half the materials spilled were recovered. All values are based on the vaporized material and represents a very small amount of loss. The material is being pumped and moved to onsite storage to facilitate recovery and treatment of the material. All recovered liquid material is being placed in tanks 778, 21, 22, and 26, all of which are properly configured and permitted to store this material. On June 14, 2012, the site began the process of understanding the constituents of the steam cracked naptha that may have been released to the air by performing material balance calculations. During the first 24-48 hours of the incident response, the intial assumptions were that a majority of the material was being contained with minimal evaporative losses. Emissions reporting was based on the initial vaporization of material from the leak duration. Sample of the stored and liquid material were collected from multiple areas and storage facilities to help develop a more definitive material balance of the total steam cracked naptha released. As a precaution, at 1230pm on Jun 14, 2012, approximately 400 employees and contractors in the impacted areas of the complex were tested for potential exposure. ExxonMobil believes that none of these individuals will have any adverse impacts. The site conducted regular monitoring at the fence line every four hours and in three unit areas on an hourly basis during the incident response activites. All fence line readings remain below detection. ExxonMobil Industrial Hygiene personel continue to conduct air monitoring and are verifying safe conditions for areas were personnel are working. Fenceline monitoring will be conducted until the steam cracked naptha material in tank 21 and RB-1 have been treated through the Refinery Wastewater Treatment facilities. Firefighting foam was added to the sewer system every 1-2 hours to minimize the amount of evaporative losses. This foam did not impact wastewater treatment operations or capabilities in the quantities utilized during this incident.
22.0 pounds

Tank 784 Socks
Cause: Due to the degradation of the socks of the storage tank over time, there was a release of benzene.Tank 784 socks leaked 0.75 lb/hr of benzene. OSHA requires a Highly Hazardous Entry permit to go to the top of the tank and fix the problem.

Followup: No

Notes: On 5/29/12/ at approximately 17:00 hours, the socks on the benzene tank were replaced and the release was secured. In the initial report on 5/28/12, the refinery stated that it expected reportable quantity for benzene to be exceeded. However, in the follow-up letter on 5/31/12, the refinery stated that no reportable quantities were exceeded.

OLA-2X gas compressor
Cause: On November 20, 2013 at approximately 2 PM, the OLA-2X gas compressor tripped due to high vibrations; causing material to be released to the site's flare gas system. Follow-up investigation results indicate that the drain line for the compressor coupling guard became plugged with an extensive amount of coke, allowing oil to build up and degrade the inside of the coupling guard. Over time, the oil degradation impinged on the coupling, causing the high vibrations. The Reportable Quantities for ethylene, propylene, butadiene, isoprene, benzene, nitrogen oxide, and sulfur dioxide was exceeded as a result of this event.

Followup: Yes

Notes: Immediately after the trip, unit shutdown procedures were executed and feed was safely removed from the unit. Air monitoring was conducted on November 20 and November 21 and all results were below the level of detection. Insulated the coupling guard drain line. Will evaluate installing a manometer on the coupling guard to attempt to measure air flow in the coupling guards and establish a monitoring program to determine if coke is accumulating in the coupling guards. Note: the initial report claims that plugged drain lines are not able to be detected or repaired, so the incident was not preventable. However, the follow-up report claims that air monitoring might detect coke accumulation and allow prevention.
165.0 pounds

OLA-2X Gas Turbine
Cause: On September 29 at approximately 11:20 PM, the OLA-2X gas turbine tripped causing material to be released to the site's flare gas system. The shutdown was caused by a loss of flame in the gas turbine. Initial findings indicate that a change in power augmentation steam quality caused the loss of flame. An investigation is underway to determine the root cause of the change in steam quality.

Followup: No

Notes: Feed was safely removed from five of the seven furnaces to minimize the load on the flare system and emissions to the atmosphere. The remaining two furnaces were operated at minimal rates to minimize start-up emissions. Air monitoring was conducted on September 30, 2013 and all results were below the level of detection. This incident is under investigation to determine the root cause of the change in steam quality. Short term mitigation steps have been implemented to ensure consistent steam delivery to the gas turbine.
386.0 pounds


Cause: On May 21, the Baton Rouge Chemical Plant experienced a turbine trip at the OLA-2X unit. The material released was sent to the site flare gas system. After further investigation, it was determined that this event was due to the failure of the fuel gas control valve servomechanism actuator. The servomechanism actuator failed due to particulate matter build up in the hydraulic oil system.

Followup: No

Notes: Immediate remedial action was to reduce unit feed rates to help minimize emissions. The hydraulic oil filters and servomechanism actuators were replaced prior to restarting the machine.
414.0 pounds

No Information Given
Cause: Exxon Chemical had a hole in a valve that is the source of the release. Due to prompt incident responses to mitigate the duration, no reportable quantities were exceeded.

Followup: No

Notes: As of March 19, 2014 the cause for release is unknown and is ongoing. They are in process of blocking in the line. Approximately 19 pounds of isoprene and 110 pounds of flammable vapors were released during the incident.
19.0 pounds