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Phillips 66 (2418), Belle Chasse
Releases of Sulfur Dioxide
| LDEQ Accident Number Accident Date |
Point Source(s) | Notes | Amount of Release |
| No LDEQ Reported 2005-07-29 | 308F-D-1 Low pressure flare | Cause: The liquid/gas pressure relay on transformer XFR 5CE at electrical substation 5C unexpectedly tripped breaker VCB 3CG. Followup: Yes Notes: Claimed preventative maintenance could have been used, but the failure was unforeseeable. The level of SO2 exceeded that of a reportable level. | 653.4 pounds |
| No LDEQ Reported 2005-07-25 | Low Pressure Flare | Cause: A contractor came into contact with the instrument air supply line for the FCC Unit's K-2A Supplemental compressor. This caused the lines to separate and for air to leak. Followup: No information given Notes: It was immediately repaired and they claimed to go over similar air supplies. | 251.0 pounds |
| No LDEQ Reported 2005-07-05 | FCC Unit #1291 | Cause: The FCC Unit #1291 system tripped off-line due to a false airflow alarm. Followup: No information given Notes: They claimed they restarted it and it is now safe and secure. | 314.0 pounds |
| No LDEQ Reported 2005-06-07 | X-4 and X-5 exchangers in the coke fractioner | Cause: The compressor second state knockout drum received a high level alarm. Inadequate cooling of verhead vapors at the X-4 and X-5 exchangers in the coke fractioner caused the 891-K-1 compressor to trip offline Followup: No information given Notes: They claimed they changed operational procedures and the compressor was restarted. | 317.0 pounds |
| No LDEQ Reported 2005-05-10 | (308F-D-1) Low Pressure Flare; (308F-D-2) High Pressure Flare; (301-D-3) CO Bypass Stack; (591-D-21X) SRU Incinerator | Cause: Entergy experienced a ground fault and the backup supply failed to switch in a timely manner. Forced most process units to shutdown resulting in flaring and venting of CO. Two pressure valves relieved to the atmosphere. Followup: No Notes: With most of the process units down, there was isufficient feed to keep the SRU tail gas treater online. The tail gas from SRU 591 was routed directly to the SRU incinerator until other refinery process units restarted to provide sufficient feed to support stable TGT operation. There was some smoking form the flares. | 47,071.0 pounds |
| No LDEQ Reported 2005-05-02 | Low Pressure Flare | Cause: The inlet temperature signal increased unexpectedly at the suction drum and the recycle flow rate increased causing the compressor to trip off line due to a high amperage reading fromt eh compressor's motor. Followup: No Notes: Operational changes were made immediately to correct the temperature signal at the suction drum and the compressor was restarted. | 188.5 pounds |
| No LDEQ Reported 2005-03-08 | Saturated Gas processor 7991 -K-1 | Cause: Saturated Gas processor 7991 -K-1 tripped off line due to a mechanical trip failure of compressor metal end blades. Followup: No information given Notes: None | 407.8 pounds |
| No LDEQ Reported 2005-01-23 | 301-D-3 FCC Generator Flue Gas Bypass Stack;308F-D-2 High pressure flare | Cause: FCC regenerator flu gas expander, 1291-k-1 tripped offline due to a mechanical failure causing an emergency shutdown of the FCC Unit Followup: Yes Notes: They claimed preventative maintenance is possible, but just the regenerator failing was unforeseeable. | 5,016.0 pounds |
| No LDEQ Reported 2005-01-03 | 592-X-1 Heat exchanger | Cause: There was a small leak in the 592-X-1 heat exchanger which caused the temperature to drop which in turn made there no proper control for the sulfur conversion at the 592 unit. Followup: No information given Notes: It was below the RQ standard of SO. | 389.5 pounds |
| No LDEQ Reported 2006-11-23 | 301-D-3 FCC Regenerator Flue Gas Bypass Stack; 308F-D-1 Low Pressure Flare; 308F-D-2 High Pressure Flare | Cause: The FCC process control system malfunctioned causing upset operating conditions at the FCC Unit. This malfunction caused an immediate and unecpected shutdown of the entire FCC Unit. Followup: yes Notes: According to the report: "Although preventative maintenance procedure exist, conditions of this type cannot be anticipated. An investigation is continuing to determine the root cause of this accident." | 606.0 pounds |
| No LDEQ Reported 2006-08-17 | 308F-D-1 Low Pressure Flare; 308FD2 High Pressure Flare | Cause: An electrical fault caused a loss of power to the Alkylation Unit cooling tower and tripped the Delayed Coking Unit compressor and other equipment off line. Followup: No Notes: Stabilized unit allowing restart of the 891K1 compressor and stopping of the flaring off of 491V9 | 2,338.0 pounds |
| No LDEQ Reported 2006-08-09 | 308F-D-1 Low Pressure Flare | Cause: During Coke Drum switch the actuator on isolation valve XV627 malfunctioned which in turn caused the compressor kickback valve to open. Followup: No Notes: Coker unit operations and pressures were stabilized and the valve to the flare was closed. | 3,364.1 pounds |
| No LDEQ Reported 2006-06-19 | 308F-D-2 High Pressure Flare | Cause: The Pressure Swing Adsorption Unit tripped off line due to leaking of the Repssure Safety Valve to the HP Flare System. Followup: No Notes: PSV was isolated from the unit. An investigation is continuing to determine the root cause of this accident. | 1.0 pounds |
| No LDEQ Reported 2006-06-12 | 308F-D-2 High Pressure Flare | Cause: The reflux pump 294L4B att he Low Sulfur Gasoline Unit experienced a seal failure. Followup: No Notes: The Low Sulfur Gasoline Unit was taken off line and shutdown. | 1.0 pounds |
| No LDEQ Reported 2006-06-07 | 308F-D-1 Low Pressure Flare | Cause: Coke fine particles clogged downstream of the valve causing liquid levels in V16 to increase. Followup: No Notes: It seems these coke particles had accumulated failry quickly near the valve due to the manner in which the outlet valve had been operating over the past several drum switch cycles. | 641.5 pounds |
| No LDEQ Reported 2006-06-06 | 308F-D-1 Low Pressure Flare | Cause: The level float column in the 1291 V 15 Sour Water Drum malfunctioned causing its level controller OLC 180 to open and caused a higher than normal rte of sour water and hydrocarban to inter the Sour Water Stripper Flash Drum v12. Followup: No Notes: The OLC 180 controller valve was manually closed and then re opened to establish a proper water level in the Sour Water Drum. | 128.0 pounds |
| No LDEQ Reported 2006-05-18 | 308F-D-1 Low Pressure Flare | Cause: The 891-K-1 compressor tripped off line due to a faultry level indicator on the high level alaerm in the compressor interstage drum. There was foreign material collecting and plugging the level bridle on V-16. Followup: No Notes: The liquid levels in the interstage drum were drained manually and the circuit breaker for the compressor was reset and the compressor put back on line. A periodic flush of the V16 level bridle with fresh water is the corrective action. | 1,081.6 pounds |
| No LDEQ Reported 2006-05-16 | 308F-D-1 Low Pressure Flare | Cause: Malfunction with the bus bar caused the main circuit breaker supplying power to the Crude Unit 191, Saturated Gas Unit 7991 and the WWTP to trip. The power interruption caused unit upsets at the Crude Unit and Hydrotreating Unit 292. Followup: No Notes: Immediately switched power source to an alternative feeder. | 3,401.0 pounds |
| No LDEQ Reported 2006-04-26 | 308F-D-1 Low Pressure Flare | Cause: Problems with the coke cutting system required a switch of drums which reduced the flow to the compressor and caused a compressor kickback valve to open to the flare. Followup: No Notes: Pressures were stabilized and the valve was closed. | 1,895.0 pounds |
| No LDEQ Reported 2006-03-13 | 308F-D-1 Low Pressure Flare | Cause: Failure of the motor for the 592K1A blower Followup: No Notes: The release was due to 2 problems: first the motor powering the blower failed. Second when an alternate blower was placed in service the discharge valve at the blower failed to open due to a hidden mechanical failure. The valve was repaired. | 1,839.0 pounds |
| 101938 2007-12-28 | Diesel Hydrotreater Unit | Cause: A small fire occurred in the convection section of the Diesel Hydrotreater Unit 293 in one of the tubes. While in the process of isolating the H-1 Heater for inspection and repair of the tube, the tube completely failed resulting in a fire in the entire convection sectino of the heater. Followup: No Notes: The Refinery's Fire Brigade and Emergency Response Teams were activated and the fire was extinguished. No offsite impacts were noted during air monitoring. | 240.8 pounds |
| 100206 2007-10-16 | 292-FF, 308F-D-1 Low Pressure Flare | Cause: Vapor leak coming from a tube at the exchanger. Unit 292 was depressurized and shut down which caused flaring. Followup: Yes Notes: Determined that preventative maintenance procedures could not prevent this accident. | 673.0 pounds |
| 99785 2007-09-27 | 308F-D1 Low Pressure Flare | Cause: The Delayed Coking Unit was in hot circulation and preparing for startup after unexpectedly losing its coke cutting water pumps and its compressor (891 K-1) tripped off line due to high liquid level in the compressor suction drum 891-V-12, unexpectedly carried over to V-15. The compressor's suction stream is automatically diverted to the Low Pressure Flare during an emergency shutdown. Followup: Yes Notes: Investigation to determine the cause of liquid carryover from the Delayed Coking Unit combination tower overhead drum. The refinery claims that there was no offsite impact. | 683.8 pounds |
| 99023 2007-08-29 | 308F-D-1 Low Pressure Flare, 308F-D-2 High Pressure Flare | Cause: Followup: Yes Notes: | 605.0 pounds |
| 97401 2007-06-26 | 308F-D-1 Low Pressure Flare | Cause: The Delyaed Coking Unit compressor 891 K-1 tripped offline due to high level in the suction drum, 891-V-15. Liquid from the DCU combination tower overhead drum, 891-V-12, carried over to V-15 due to plugged strainers on the V-12 on the water boot pumps and hydrocarbon pumps or some other flow restriction. The compressors suction stream is automatically diverted to the Low Pressure Flare during and emergency shutdown of the compressor. Followup: Yes Notes: Operators tried to mitigate the accident by cleaning the strainers and tried to draw liquid from V-15 to the flare drums. Attempts were unsuccessful and the K-1 compressor still tripped. Compressor was purged of liquid and restarted. ConocoPhillips claims "no offsite impact" from fenceline monitoring. | 1,136.0 pounds |
| 96490 2007-05-23 | Carbon Monoxide Bypass Stack Low Pressure Flare, High Pressure Flare, SRU incinerator Stack, 191-PV-105, Heaters 410-PSV-62 Induction gas relief valve (APC-105), Low Pressure Flare, High Pressure Flare Low Pressure Flare (308F-D-1), High Pressure Flare, 191 APC-105 Low Pressure Flare, High Pressure Flare, 191-PV-105 | Cause: During a rain storm the line from Entergy's substation tripped. The loss of power forced most of the refinery's process units to shutdown resulting in flaring. While shutting down the 191 crude unit the pressure controller relieved vapors and liquid hydrocarbons from a vent at the top of the Vacuum Tower. The hydrocarbons ignited and caused a fire at the top of the Vacuum Tower. With most of the process units down there was insufficient feed to keep the SRU tail gas treater online. The tail gas was routed to the SRU incinerator. When units were started up again they required more flaring for prepare for recommissioning. Followup: No Notes: Determined that although there are back up systems there are no ways to prepare for these types of power outages. Electrical department will preform preventative maintenance and replacement of components. 191-PV-105 pressure controller at the crude unit no longer vents to the atmosphere. Piping was installed that routes gases from this vent directly to the flare. | 42,788.0 pounds |
| 94176 2007-02-23 | Incinerator Stack | Cause: The condensate boot on the Tail Gas Treater Unit reboiler malfunctioned resulting in a loss of temperature on the 591-V-33 Stripper. This caused excess emissions of SO2. Followup: No Notes: | 492.9 pounds |
| 94025 2007-02-07 | FLARE - 308F-D-1 Low Pressure Flare | Cause: A 34.5KV lightning arrestor failed near breaker W5305 (Carlisle #1 Line Bus, and an insulator failed on the disconnect switch on the other side of breaker W5305 (ConocoPhillips # 2 Line Bus). ConocoPhillips Alliance breakers W5305, W5301, W5304 tripped along with Carlisle W6922 breaker. All of these de-energized ConocoPhillips #2 Line to the plant leading to the Coker Compressor to trip off the line. The compressors suction stream was automatically diverted to the Low Pressure Flare (308F-D-1) during the emergency shutdown of the compressor. Followup: No Notes: Three arrestors on breaker W3505 were replaced, as well as a failed insulator. Preventive measures are in place, but incidents of this type could not be anticipated by the prevention measures. A further investigation to discover the root cause of the malfunctions is ongoing. | 646.9 pounds |
| 93785 2007-02-07 | 308-F-D-1 Low Pressure Flare | Cause: A 34.5KV lightning arrestor failed at Entergy substation. An insulator also failed on the disconnect switch. The opening of these breakers caused the Coker Compressor to trip off line. The compressor's suction stems is automatically diverted tot he Low Pressure Flare. Followup: No Notes: Three arrestors and a failed insulator are being replaced. | 646.9 |
| 110898 2008-11-19 | 308F-D-1 (Low Pressure Flare); 308F-D-2 (High Pressure Flare); 191-FF (191-PSV-009A); 191-FF (191-PSV-011) | Cause: On 11/19/09, the refinery "experienced an unexpected internal electrical power phase to ground fault." This fault caused a power interruption from internal Substation 5D to the Crude Unit 191 and resulted in the loss of most of the Crude Unit's pumps and several fin fans causing a major unit upset and emergency shutdown. These upset operations subsequently caused the Atmospheric Tower's pressure relief valve (191-PSV-009A) to open to protect the upper section of the Atmospheric Tower.
An attempt to circulate the liquid inventory in the Vacuum Tower (VT) back to the Crude Tanks caused as unexpected high liquid level and the VT pressure relief valve (191-PSV-011) opened up to protect the upper section of the VT. This relief valve relieved vapors, liquid hydrocarbons, and crude oil from a vent at the top of the VT.
The loss of the Crude Unit forced most of the refinery's process units to shutdown resulting in intermittent flaring.
Following the shutdown and the re-establishment of power to substation 5D, the process of restarting several refinery units was initiated. The Coker Unit's Compressor (891-K-1) motor amp limit controller (PJC-404) unexpectedly opened the flare valve (PPC-998) due to a very high motor amperage surge at its initial start.
Flares smoked intermittently throughout shutdown and startup events. Fenceline monitoring indicated "no offsite impact."
Fenceline monitoring Followup: No Notes: Immediate: Units were shut down until electrical supply was repaired. After a formal investigation, the cause of the incident was determined to be a loose connection between the bus and runback rod that put enough electrical load on the connecting bolt to melt it thus creating the ground fault. Connecting bolts are now inspected and replaced as necessary, COP electricians are being further trained, and a QC checklist and testing procedures to verify proper electrical connections have been implemented. Discharge classified as "Extremely Hazardous Substance" Regulated by OSHA HazCom | 1,951.0 pounds |
| No LDEQ Reported 2008-10-16 | 4000 hp compressor --FLARE | Cause: Trip of 4000 hp compressor caused by a low oil alarm trip caused by an air bubble in the lube oil system. Followup: Yes Notes: New operrating procedure developed and implemented to prevent the problem from reoccuring. Verbal report | |
| No LDEQ Reported 2008-09-21 | 591-D-21 (Sulfur Recovery Unit Incinerator) | Cause: Startup after Hurricane Gustav Followup: No Notes: *Same State Police number as an incident on 9/19/2008, but different NRC and LPEC numbers. Unsure if itÕs a separate incident or related. No LDEQ report.* Non-optimal shutdown performed prior to the Hurricane Gustav evacuation inorder to reduce emmisions during shutdown. There was insufficient time to perform 4-6 process to remove residual sulfur to As a result residual sulfur was released directly to the incinerator during startup. | 787.0 pounds |
| No LDEQ Reported 2008-09-19 | 308F-D-1 Low Pressure FLARE | Cause: Followup: No Information Given Notes: High pressure in the Sulfur Recovery Unit 591 resulted in part of the acid gas (Hydrogen Sulfide) feed to be routed to the Low Pressure flare. Sulfur dioxide did not exceed reportable quantities. No mention of Hydrogen sulfide emissions in report. | 206.0 pounds |
| No LDEQ Reported 2008-09-18 | 591-D21 (SRU incinerator) | Cause: Restarted in "cold" start-up mode after Hurricane Gustav. Followup: No Information Given Notes: Due to hurricane start up Tail Gas Treater Unit (TGT) and Sulfur Recovery Unit (SRU)started up at the same time, rather than with the TGT already running. This sent more gases than usual directly to the incinerator causing increased emissions. Units were stabilized. | 1,906.0 pounds |
| No LDEQ Reported 2008-09-14 | 308F-D-1 Low Pressure FLARE | Cause: Dduring start up of Coker unit after Hurricane Gustav evacuation Followup: No Information Given Notes: Extra material was stored in the Coker Feed Tanker to prevent solidification and pluggage of the Coker unit feed system after Hurricane Gustav. This also caused higher than usual pressure in the Coker Fractionator Overhead and the Compressor suction drum (891-V-15), which caused the flare vlave to open. Compressor turned on but flaring continued until material was released from feed and no longer affected the overhead. | 1,506.0 pounds |
| No LDEQ Reported 2008-08-28 | Fluid Catalytic Cracker (FCC) Unit | Cause: The Fluid Catalytic Cracking Unit was shut down to repair an eroded slide valve stem at the regenerator. Followup: No Notes: Alkylation Unit placed on standby and low sulfur gasoline unit lost feed. All three units restarted. Emissions Below reportable quanitities. | |
| No LDEQ Reported 2008-07-19 | Distillate Hydrotreater (DHT) | Cause: Followup: YES Notes: Distillate Hydrotreater shut down and restarted to make repairs on a leak in a pump seal. Courtesy notification. Verbal report made but no but no written report followed. | 1.0 pounds |
| No LDEQ Reported 2008-06-28 | 308F-D-1 (Low Pressure Flare), 591-D-21-X (SRU Incinerator Stack) FLARE | Cause: Followup: Yes Notes: Acid Gas flaring due to 592-H-1 heater going offline after loss of flame caused by pressure fluctuation in the Sour Water Stripper vessel affecting feed stream quality to SRU-592 Unit. 592-H-1 heater relit and brought back on line. | 2,701.6 pounds |
| No LDEQ Reported 2008-06-22 | Fluid Catalytic Cracker (FCC) Unit | Cause: Followup: Yes Notes: Restart of FCC unit after shutdown in incident # 106591 on 6/19/2008 due to a problem with a slide valve. Facility experimenting with "Full burn mode" during start up to try to reduce emissions. Investigation into root cause to take place. | 181.0 pounds |
| No LDEQ Reported 2008-06-20 | Fluid Catalytic Cracker (FCC) Unit | Cause: Followup: no Notes: Courtesy call and notice of potential falring during a shutdown because of a slide valve problem with the FCC. Emmissions Below Reportable Quantities. | 156.0 pounds |
| No LDEQ Reported 2008-06-14 | (308F-D-1) Low Pressure Flare, (308F-D-2) High Pressure Flare, (301-D-3) CO Bypass Stack | Cause: Followup: Yes Notes: FCC slide valve mechanical failure discovered while the FCC was down for maintenance. FCC restarted in full combustion mode and vented through the Carbon Monoxide boiler which was then later restarted. Investigation into how to prevent further emmissions during start up to follow. | |
| No LDEQ Reported 2008-06-07 | Fluid Catalytic Cracker (FCC) Unit | Cause: Followup: No Notes: (See Incident Report 106039) Incident caused by a starting up the Fluid Catalytic Cracker (FCC) after it underwent repairs for a faulty valve. Investigated on 6/28/2008 | |
| No LDEQ Reported 2008-06-03 | Fluid Catalytic Cracker (FCC) Unit, 308-D-1 Low Pressure FLARE, 308F-D-2 High Pressure FLARE, 301-D-3 CO Bypass Stack | Cause: Followup: Yes Notes: FCC shut down to repair a crack. During repairs, a broken valve was discovered and also repaired (#106247). Emissions released during startup of FCC and below reportable quantities. Investigation into procedures to prevent flarting during shutdown/startup | 848.2 pounds |
| No LDEQ Reported 2008-05-22 | Unit 294 FLARE | Cause: Followup: Yes Notes: Courtesy Call. Below Reportable Quanitities. | 449.0 pounds |
| No LDEQ Reported 2008-05-17 | FLARE-PSV-84 relief valve on Reactor (491-V-49) | Cause: Valve failure cause by a power surge from lightening. Followup: Yes Notes: Incident due to a valve failure caused by a power surge from lightning. Motor control and trim on valve fixed. | 250.0 pounds |
| No LDEQ Reported 2008-01-25 | Diesel Hydrotreater Unit 293 | Cause: Start Up, Shut Down --Unit 239 restarted after repairs completed on failed tubes Followup: No Notes: Community monitoring during a planned emission. Incident considered a courtesy notification for potential flaring. | |
| 119864 2009-12-05 | No information given | Cause: The 592 Sulfur Recovery Unit (SRU) has 3 combustion air blowers. Usually, 2 are on line. On 12/5, one of the two operating blowers tripped due to a thermal overload. This drop in air discharge pressure activated the Low Combustion Air Pressure alarm which shutdown combustion in the SRU Reaction Furnace. This activated the Sour Water Stripper (SWS). Followup: No Notes: The refinery initiated "sulfur-shedding" procedures until SRU could be brought back online. | 241.0 pounds |
| No LDEQ Reported 2009-10-07 | 308F-D-1 (Low Pressure Flare) | Cause: "During the planned and controlled shut down of the Saturated Gas Unit's Compressor for an emergency maintenance repair, the Diesel Hydrotreater Overhead gases were re-routed to the FCC Unit's compressor. While routing the gases to the FCC compressor, increased pressure drop caused the Diesel Hyrdrotreater overhead pressure controller to open the Low Pressure Flair (308F-D-1). The overhead pressure was adjusted which subsequently stabilized operations resulting in the closing of the flare valve..." Followup: Notes: After a root cause investigation, it was determined that the a corrective action should be implemented. The Diesel Hydrotreater's Overhead pressure "shall be increased prior to routing that streat to the FCC compressor. This step should minimize the chance of opening the flare valve in the overhead system and also overcome the pressure drop phenonenon experienced while routing the gases to the FCC compressor. Fence-line monitoring reported "no offsite impact." | 407.3 pounds |
| 116461 2009-07-14 | 308F-D-1 (Low Pressure Flare) | Cause: The FCC Regenerator Flue Gas Expander, 1291-K-1, tripped offline due to a mechanical failure causing an emergency shutdown of the FCC Unit. Flaring occurred from the Low Sulfur Gasoline (LSG) Unit 294 and the Diesel Hyrdrotreater Unit 292 due to the emergency shutdown of the FCC Unit. There was also a small fire on the Expander's lube oil and seal oil piping that occurred incidentally with the Expander mechanical failure, but was quickly extinguished with a fire extinguisher. Followup: No Notes: FCC Unit initiated emergency shutdown procedures. | 2,522.4 pounds |
| 115847 2009-06-20 | 308F-D-1 (Low Pressure Flare) | Cause: Following various maintenance repairs at the Alkylation Unit, start-up procedures for the FCC Unit were initiated. The FCC Unit started up and some flaring at the Low Pressure flare (308F-D-1) occurred. There were some emissions of sulfur dioxide that occurred during the flaring event, but below RQ. Followup: No Notes: The Alkylation and Low Sulfur Gasoline Units were subsequently started up following the FCC Unit with no further flaring or venting noted. Community monitoring was performed throughout the start-up of all three refinery process unites with no offsite impact noted. | 298.0 pounds |
| 115614 2009-06-12 | 308F-D-1 (Low Pressure Flare); 308F-D-2 (High Pressure Flare) | Cause: Approximately three hours following the installation of the level transmitter, operating conditions within the saturated gas unit began to show periodic spikes of liquid carryover into the inlet of the compressor (7991-K-1) by having periodic compressor speed slowdowns. The liquid carryover seems to have been attributed to the level transmitter malfunctioning both in response time and level indication. The next day, the Saturated Gas Unit Compressor unexpectedly shut down due to a high level alarm in the compressor's suction drums (7991-V-7 and V-8) which get their feed from the Absorber/Stripper column (V-2). Several process unites then flared due to inlet gases being routed to the FCC Compressor and subsequent upset conditions from suddenly swinging into a different compressor system. This eventually caused the FCC compressor to shut down. When the FCC Compressor shuts down in an emergency, it causes the entire Low Sulfur Gasoline Units (among other operations) to shutdown as well.
*Could also be classified as start up/shut down. Followup: No Notes: Immediately tried to restart the Saturated Gas Unit's compressor as well as route the inlet gases to the FCC Compressor which began to also have de-stabilizing operating conditions. "No offsite impact noted throughout the event." | 1,446.0 pounds |
| 114566 2009-04-30 | 308F-D-1 (Low Pressure Flare) | Cause: On April 30, 2009 at approximately 2:40 AM, the Coker compressor unexpectedly tripped off-line. At approximately 2:41 AM the suction drum flare valve opened, which it is designed to do when the compressor experiences an unexpected complete shutdown. The suction stream is automatically diverted to the Low Pressure Flare (308F-D-1) during an emergency shutdown. Followup: No Notes: The compressor was started and brought online following review of alarm and trip logs. | 1,871.0 pounds |
| 114066 2009-04-08 | 308F-D-1 (Low Pressure Flare) 308F-D-1 (Low Pressure Flare); 191-PSV-009 | Cause: The 891-K-1 Compressor tripped off-line due to a high liquid level inside the first stage suction drum (891-V-15). This was caused by high liquid levels in the fractionator tower's reflux drum (891-V-12) due to coke fines plugging the filters of the L-11 reflux pumps and L-13 Sour Water pumps at an unexpectedly rapid rate.
The compressor's suction steam is automatically diverted to the Low Pressure Flare (308F-D-1) during an emergency shutdown of the compressor. Monitoring at the refinery permitter was performed and "there was no offsite impact." Followup: No Notes: The compressor was started and brought online as soon as proper levels could be established in the first stage suction drum. An investigation is in process to determine the cause of the high levels in the first stage suction drum (which caused the compressor to trip). | 1,254.0 pounds |
| 113974 2009-04-06 | 308F-D-1 (Low Pressure Flare); 191-PSV-009 Unit 191-PSV-009 | Cause: A power failure occurred as a result of grid failure due to scheduled maintenance by Entergy. Entergy's method did not allow for ConocoPhillips to secure an alternative source while the main grid was down. The refinery thus had to initiate an emergency shutdown. As a result, the refinery had to employ the low pressure flare. Followup: No Notes: Entergy has proposed a three phase project that will build additional substations within the electrical power grid over the next five to eight years to improve its reliability. Entergy is currently seeking federal funding for this project. | 12,914.0 pounds |
| 113242 2009-03-08 | 308F-D-1 (Low Pressure Flare) | Cause: Problems with the Coker drum steam condensate operations caused inadequate heating of the"inactive
Coke drum. To avoid shutting down the Coker Unit, Operations personnel switched Coker feed from teh "active" drum into the "inactive" drum that was much cooler than normal operating systems.
The switch into a cooler coke drum reduced the flow to the 891-K-1 compressor and caused the "compressor kickback" control scheme to activate. This scheme caused the compressor kickback valve to open, sending additional flow to the compressor's suction drum (891-V-15). The pressure in the compressor suction drum increased to the point that the pressure control system opened the valve to the Low PRessure Flare (308F-D-1). Followup: No Notes: Coker unit operations and pressure were stabilized and the valve to the flare was closed. | 627.0 pounds |
| 113178 2009-03-05 | 308F-D-1 (Low Pressure Flare) | Cause: The refinery experienced an unexpected trip in the Coker Compressor which resulted in an unexpected release of SO2. Approximately 1,480.5 lbs of S02 was released.
The 891-K-1 Compressor tripped off-line due to a low seal oil liquid level inside Tank (891-V-23). This was due to a lack of pressure controller (PCV-152) causing sea oil to spill back into the main Seal Oil Tank (T-2B-X) and not holding enough pressure to keep the overhead seal oil tank properly filled.
The compressor's suction sctream is automatically diverted to the Low Pressure Flair (308F-D-1) in an emergency shutdown. Followup: No Notes: The compressor was started and brought online as soon as proper Seal Oil level could be established in the Overhead Seal Oil Tank. "No offsite impact detected." | 1,480.5 pounds |
| 112738 2009-02-13 | 308F-D-1 (Low Pressure Flare); 1391-FF (1391-PSV-009); 301-D-3 (CO Bypass Vent) | Cause: During the startup of the FCC Unit following a 36 day refinery maintenance turnaround outage, the unit unexpectedly transitioned to partial-burn combustion in the catalyst regenerator for less than an hour before the bypass vent was closed.
Shortly after starting up the Reformer Unit during a test of newly installed burners in heater 1391-H-4, a high concentration of very light material (hydrogen and propane) caused the Depentanizer tower's overhead pressure to rise, resulting in the PSV-009 to relive for approximately 3 minutes. This reduced the pressure and the PSV re-sealed properly.
While starting up the Coker Unit, light material in its feed stream from the Crude Unit also caused an unexpected increase in pressure in the suction drum of the compressor which caused the flare valve at the suction drum to open into the low pressure flare. Compressor suction drum pressure was stabilized as feed quality to the Coker Unit improved and the flare valve was closed. Followup: No Notes: Operations has developed for its operators responsive drills for rapidly occurring unstable conditions which will eventually help minimize impact of emissions to the environment. | 161.0 pounds |
| 111891 2009-01-08 | 308F-D-1 Low Pressure Flare 308F-D-1 Low Pressure | Cause: A notification for the controlled shutdown of the entire plant was made on January 7, 2009. On January 8, the Sulfur Recovery Unit/Tail Gas Treater (SRU/TGT) was determined to have pluggage issue that precipitated the premature shutdown of the SRU/TGT. This led to flaring and SO2 emissions. The loss of the SRU/TGT required the initiation of a controlled shutdown of the remaining process units which contributed additional Sulfur Dioxide emissions. Followup: No Notes: An immediate shutdown was conducted of refinery process units. An investigation of the SRU upset is in progress and "will be reported in a subsequent letter." | 9,757.0 pounds |
| 126678 2010-09-24 | 308F-D-1 (low pressure flare) and various process heaters | Cause: During maintenance activities, "amine stripper vessel experienced unexpected level swings" and "SRU (sulfur recovery unit) waste heat boiler unexpectedly tripped offline due to its flame scanner no longer detecting a flame at the burner. Several attempts that were made to re-light the burner were unsuccessful due to igniter malfunction" -- had to flare excess. Followup: No Notes: "Routed acid gas feed stream to the LP flare and immediately implemented the sulfur shedding plan...root cause investigation has been initiated." Detailed refinery letter only in this file. No LDEQ Report. | 26,236.0 pounds |
| 126166 2010-09-06 | SRU incinerator | Cause: Emissions due to scheduled maintenance on Tail Gas Treater. Followup: No Notes: "The FCC (fluid catalytic cracking) unit was taken offline prior to the TGT shutting down in a controlled manner." | 146,565.0 pounds |
| 126043 2010-08-30 | low pressure flare | Cause: Controlled flaring for inspection and maintenance--remaining gases from the Fluidized Catalytic Cracking Unit's recovery section routed to the Low Pressure Flare while shutting down several refinery units Followup: No Notes: none--planned flaring | 81.0 pounds |
| 124556 2010-06-30 | FLARE: Sulfur package | Cause: Refinery stated that "the root cause of this incident was due to sour gas not being transferred from the flare to the Sulfur Package in a timely matter..." The root cause analysis provided by ConocoPhillips determined that this incident was due to careless operation by personnel. Followup: No Notes: RQ. LDEQ report states, "this is an area of concern with emission point 308F-D-1 (Low Pressure Flare) of the facility's permit, Permit No.2779-V2.LAC 33:III.905.A: Failure to maintain air pollution control facilities." | 838.0 pounds |
| 123980 2010-06-05 | low pressure flare | Cause: "the Crude Unit's Vacuum Tower experienced a flooded liquid condition which caused its overhead pressure control valve to open to the Low Pressure Flare. The cause of this condistion seems to be the Vacuum Tower's Bottoms section was experiencing unexpected problems achieving adequate flow of its product stream to the Coker Unit." Followup: No Notes: "the Tower bottoms product stream was eventually routed back to Crude Tankage until the conditions in the lower half of the Vacuum Tower stabilized and the flaring stopped." | 445.0 pounds |
| 123185 2010-05-02 | Cooling water exchanger & Coker compressor (891-K-1), Low-pressure flare (308F-D-1) | Cause: Report states that the release occurred as a result of a breaker trip in the Coker Compressor. Which seems to have originated within the compressor's motor. Followup: Yes Notes: RQ. Reportable quantity for sulfur dioxide was exceeded. LDEQ report states that "The facility will be referred to the Circuit Rider Review process for failure to submit an updated notification within 60 days of the initial 7 day letter as required by LAC 33:I.3925.A.3." An investigation is in process to determine the cause of the electrical breaker trip after which, corrective actions will be implemented. | 8,174.9 pounds |
| 122118 2010-03-13 | no information given | Cause: "process unit upset caused to go to flare" Followup: No Notes: DEQ report only in this file; no refinery letter. | |
| 121257 2010-02-04 | 891-V-11A Coke Pot Valve FLARE: Low Pressure Flare (308-F-D-1) & 891-V-11A Coke Pot Valve | Cause: Release notification form states that, during the Fractionator Tower Coke Pot, the unit operator improperly operated the Coke Pot's valves. This allowed hot, tar-like hydrocarbon material into the unit sewer, which caused a fire at the Coke Pots. FIRE. Followup: Yes Notes: RQ. The Coker Unit was shutdown in an emergency fashion while the fire was controlled and extinguished by the refinery's in-house fire brigade. Disciplinary actions were taken towards the operator and the supervisor of the Coker Unit for not following established procedures. The Coke Pot procedure was enhanced by adding another layer of protection via the requirement to physically lock "closed" the Coke Pot valves prior to unlocking the drain valves. | 659.0 pounds |
| 121257 2010-02-04 | 891-V-11A Coke Pot Valve FLARE: Low Pressure Flare (308-F-D-1) & 891-V-11A Coke Pot Valve | Cause: Release notification form states that, during the Fractionator Tower Coke Pot, the unit operator improperly operated the Coke Pot's valves. This allowed hot, tar-like hydrocarbon material into the unit sewer, which caused a fire at the Coke Pots. FIRE. Followup: Yes Notes: RQ. The Coker Unit was shutdown in an emergency fashion while the fire was controlled and extinguished by the refinery's in-house fire brigade. Disciplinary actions were taken towards the operator and the supervisor of the Coker Unit for not following established procedures. The Coke Pot procedure was enhanced by adding another layer of protection via the requirement to physically lock "closed" the Coke Pot valves prior to unlocking the drain valves. | 1,242.0 pounds |
| 121132 2010-01-11 | low pressure flare (308F-D-1) | Cause: Coker compressor went into recycle mode during shutdown for scheduled maintenance. Suction drum pressure increased causing flare valve to open. Stream diverted to Low Pressure Flare. Followup: No Notes: flare valve closed upon complete shutdown of the compressor; monitoring at refinery perimeter | 218.0 pounds |
| 134825 2011-10-24 | Low Pressure Flare (308F-D-1) | Cause: The Control Board Operator received a high temperature seal oil alarm from the Fluidized Catalytic (FCC) 1291-K-2 Compressor equipment. Operators were instructed to back flush the seal oil coolers to remove any foulant material which may have accumulated and contributed to seal oil system's high temperature. During the back flushing procedure the seal oil operating differential pressure increased due to the increased viscosity of the cooler oil. Unexpectedly the seal oil's differential pressure began to rapidly decrease below the trip pressure of the compressor causing it to trip off-line. When the 1291-K-2 compressor trips off-line, the FCC fractionator overhead flare valve opens and relieves its gases to the Low Pressure Valve (308F-D-1) until the compressor can be started. Followup: No Notes: The compressor was restarted shortly after the pressure alarm was cleared and proper differential pressures were reestablished within the compressor's seal oil system. The failed pressure regulator was replaced to minimize repeating another compressor trip due to erratic pressure readings. | 281.0 pounds |
| 133779 2011-09-03 | Flare | Cause: On 9/3/11 at 12 noon the Coker Unit was reduced to minimal operating dates due to approaching Tropical Storm Lee. This was done in an effort to extend the Coke Drum cycle time by several hours so that refinery personnel would be out of danger and not located on the tail Coke Drum structure during the highest winds of Tropical Storm Lee. The reduction in Coker feed caused the Coker compressor's surge controller kick back valve to rapidly open several times almost tripping the compressor off-line because of this surging affect. During another surge event, the compressor's kickback valve opened rapidly subsequently increasing pressure at the compressor's suction drum above its set point. When this occurred, the console board operator changed the flare valve from automatic control to manual control in an effort to prevent the flare valve from suddenly opening during future compressor surging events. When the board operator put the flare valve in manual control, the valve was already opened at 8% output and the console board operator thought he had placed the valve in manual control when the computer graphic display showed the flare valve at 0% open. When the flare valve opens, the compressor's suction steam is automatically diverted to the Low Pressure Flare (308F-D-1). The Coker compressor did not surge any further after the flare valve's control scheme was changed. The console board operator was unaware that the flare valve remained opened for hours, and when it was discovered opened, the flare valve was immediately closed and returned to automatic control status.
A root cause investigation of this flaring event revealed the from the archive history of the Distributed Control System (DCS) that at the same time that the flare valve was put in manual mode it was inadvertently opened to 8% even though the control board operator and his supervisor both reported seeing the DCS Screen display 0% on the valve when it was placed in manual. It was also discovered that ie old DCS system the flare valve had an "output" alarm anytime the valve was at or above 1% open. However during the cutover from the old to the new control system the alarm was not picked up in the migration documental. Had the alarm been in place, it would have benefited the board operator to recognize the flare valve had opened and must be closed immediately. A contributing cause in preventing the board operator from recognizing the flare valve had opened 8% was the fact the board operator, for the next hour, was in a "Major Alarm Flood" (>30 alarms per 10 min period) due to major upsets at the Alkylation Unit (part of the board operator's additional responsibilities) which was enhanced because of very low unit operational rates and ever changing weather conditions from Tropical Storm Lee. Followup: Yes Notes: The compressor's suction drum flare valve was closed and its controller was removed from manual control and returned to automatic control. Corrective actions to address the investigation findings are the following: - Review all control valves to the flare for missing output alarm configurations - Establish the compressor's flare valve with a reoccurring high output alarm at its previous set point of 1% open - Alarm Rationalization team shall review and analyze the alarm flood period surrounding this event for possible alarm improvement opportunities. These tasks have been assigned and are scheduled to be completed before the end of 2011. Weather at the time of the event was rainy and cloudy. Wind direction: 197 degrees SSW Wind speed: 20 mph | 1,695.0 pounds |
| 133792 2011-09-03 | (308F-D-1) Low Pressure Flare | Cause: On the morning of 9/3/11 around 4:45 am the 191 Crude Unit Fractionator Overhead Accumulator pump was on-line and tripped off-line unexpectedly. Its back up pump was started and put on-line but after only a few seconds it also tripped off-line. Electricians responded and found blown line fuses for both pump's starters. Further electrical meg testing indicated that the 191-L-10A pump was shorted internally but the 191-L-10B pump did not have any phase-to-ground failure. The blown line fuses were replaced and the 191-L-10A pump was restarted but tripped off-libe after running for only a few minutes. The 191-L-10A pump motor was troubleshooted and meg tested by the electricians at the starter, power cabling, and motor field boxes. All test results found no obvious phase-to-phase fault or issues for tripping. The 191-L010A motor starter was ever replaced and still the motor failed and tripped off line within a few minutes. With both critical (191-L-10) Fractionator Overhead Accumulator pumps off-line and unable to start, it was determined that the Crude Unit was to be shutdown. When the Crude Unit shuts down, the Saturated Gas Unit also must shutdown because of loss of its feed from the Crude Unit. Subsequently, various overhead gases from both the Crude Unit and the Diesel Hydrotreater Unit are routed to the Low Pressure Flare (308-D-1) when the Crude Unit must be shutdown quickly.
The root cause investigation determined that an oil mist application called the "Lubrimist System" that had been installed on both of the 191-L-10 motors had a design flaw that allowed a fine oil mist to eventually migrate and run into the interior of the motor housing causing a significant buildup of oil and dirt on the motor's stator, windings, and housing area. The 191-L-10 motors are sleeve bearing motors that use internal fans to force air across their windings for cooling. These windings eventually became oil soaked and attract contaminants and moisture from this air flow which are conductive and degrading to the motor's performance. Contamination within the motor windings caused thermal degradation (due to blocked ventilation) and electrical tracking. Electrical tracking enables currents to flow over the surfaces of the windings insulation. These currents degrade and eventually cause the insulation to fail exposing motor wiring that should be insulated, resulting in the motor having a low resistance to ground and ultimate failing. The investigation also determined that the 191-L-10 pumps had been serviced on a frequent basis in the past but their written repair history was not detailed enough that would have enabled maintenance to anticipate and possibly prevent a motor failure. Followup: Yes Notes: Several attempts were made to get the alternate Crude Fractionator Overhead Accumulator pump on-line, but it continued to trip electrically off-line. Several electrical parts of the pump were replaced but the pump continued to trip electrically off-line. It was determined that the Crude Unit and its affected downstream units were to be shutdown until the pumps could be brought back on-line without tripping off-line electrically. The Crude Unit and its affected downstream units were shutdown safely. Fence line monitoring was performed with no offsite impacts noted throughout the entire shutdown event. The investigation also determined that the "Lubrimist system" had been installed on other motors within the refinery and their installation designs shall be reviewed and improved in order to minimize the chances of oil and dirt buildup on the motor's stator, windings, and housing area. Another corrective action will be to evaluate and determine the adequacy of installing air filters to minimize containment carry through into the motor housing. Weather conditions at the time of the incident: Rainy and Cloudy Wind Direction: 117 degrees ESE Wind speed: 30 mph | 1,176.0 pounds |
| 133170 2011-08-17 | Tail Gas Treater/Sulfur Incinerator Stack (591-D-21X) FLARE: Low Pressure Flare (308F-D-1) | Cause: During operational adjustments to the air flow to SRU-592 Claus unit, the air blower discharge pressure decreased below the set point and diverted gas from the tail gas treater (TRT) to the SRU incinerator (591-D-21X) to the Low Pressure Flare (308F-D-1). Followup: No Notes: SRU operations were stabilized allowing the flare valve to be closed and the tail gas to be routed back into the Tail Gas Treater. | 355.0 pounds |
| 133170 2011-08-17 | Tail Gas Treater/Sulfur Incinerator Stack (591-D-21X) FLARE: Low Pressure Flare (308F-D-1) | Cause: During operational adjustments to the air flow to SRU-592 Claus unit, the air blower discharge pressure decreased below the set point and diverted gas from the tail gas treater (TRT) to the SRU incinerator (591-D-21X) to the Low Pressure Flare (308F-D-1). Followup: No Notes: SRU operations were stabilized allowing the flare valve to be closed and the tail gas to be routed back into the Tail Gas Treater. | 375.0 pounds |
| 132895 2011-08-02 | FLARE: Low Pressure Flare (308F-D-1) | Cause: The bottoms control valve malfunctioned and could not be closed allowing the loss of all amine liquid in the contractor vessel (410-V-3). The hydrocarbon carryover prompted the amine flash drum's (591-V-38) flare valve to open to the Low Pressure Flare (308F-D-1). Followup: No Notes: The amine contractor's bottoms control valve was manually closed to re-establish liquid levels. | 1,664.0 pounds |
| 132791 2011-07-30 | FLARE: Low Pressure and High Pressure Flares (308F-D-1 and 308F-D-2) | Cause: The Unit 1291 Fluid Catalytic Cracking (FCC) Unit's slurry pumparound pump (1291 L-6C) deteriorated and was shutdown. This disrupted cooling of the FCC Unit's fractionator tower and this was also shutdown. Overhead gases were routed to the Low Pressure and High Pressure Flares (308F-D-1 and 308F-D-2). Followup: No Notes: BRQ. No Information given regarding remedial actions because gases were routed through permitted emission points. No SPOC report available. The incident date on the LDEQ report (7/30) and the Incident report (7/31) are different. | 448.0 pounds |
| 131764 2011-06-08 | FLARE-Low Pressure Flare (308-D-1); Crude Unit Towers (191-V-6; 191-V-3) | Cause: The Crude Unit's Vacuum Tower (191-V-6) malfunctioned and the Saturated Gas Unit compressor's first stage suction drum's (7991-V-7) level instrument also malfunctioned. Gas was routed to the Low Pressure Flare (308-D-1). Followup: No Notes: BRQ. Liquid levels at both the Crude Vacuum Tower and Saturated Gas Compressor suction drum were stabilized and flaring was secured. The incident date from the incident report does not match the SPOC and LDEQ reports. There is an e-mail string between ConocoPhillips and LA gov. regarding this discrepancy. There is a note that material did go offsite in the report. | 466.0 pounds |
| 143040 2012-09-16 | Low Pressure Flare | Cause: On September 16, 2012 the Alliance Refinery began a planned and controlled start-up of its Sour Water Stripper (SWS) Unit following its unexpected shutdown for the approaching landfall of Hurricane Isaac.
With the Refomner Unit 1391 starting up concurrently, refinery hydrogen production had also begun. Refinery hydrogen product is normally routed to various units and can be routed as well to the refinery's fuel gas system.
However, due to the transient nature of refinery start-ups, select refinery units that normally consume hydrogen had not yet begin operations requiring some hydrogen production to be routed to the fuel gas system. It was discovered that this routing to the fuel gas system inadvertently caused a Fuel Gas Pressure Relief valve (410-PSV-30) to intermittently relieve to the Low Pressure (LP) Flare (308F-D-1) as it is designed. The mostly hydrogen based material became intermixed with some of the SWS overhead vapor traffic that was routed lei the LP Flare for only a very short period of time. Followup: No Notes: On 9/16/2012 there was an acccident from 1:30AM to 1:35PM (725 minutes) [it was discovered 9/16/2012 at 6:00AM]. Upon discovery of 410-PSV-30 relieving to the LP Flare, operational adjustments were made and the intermittent flaring stopped. No reportable quantities were exceeded. Linked to NRC report # 1024575. In the refinery letter they describe the pollutant released as mostly hydrogen, but the only quantity listed is for Sulfur Dioxide - 418 lbs (no emission calculations sheet attached). | 418.0 pounds |
| 142368 2012-08-27 | Low Pressure Flare and High Pressure Flare | Cause: On the morning of August 27, 2012 while shutting down the entire refinery for the expected landfall of Hurricane Isaac the Flare Gas Recovery System was taken offline due to limited Refinery fuel gas needs and the Units that process recovered flare liquids were shutdown. Followup: Yes Notes: Minimized flaring emissions by practicing good combustion practicies and making sure the highest flaring contributors were already taken offline prior to shutting down the FGRS. An investigation will commence following Alliance Refinery's recovery from the Impact of Hurricane Isaac. | 1,916.0 pounds |
| 146671 2013-02-14 | Low Pressure Flare | Cause: Power was inadvertently interrupted to the electronic speed governor for the Fluidized Catalytic Cracking (FCC) Unit's Wet Gas Compressor. The governor performed as designed, reducing the compressor's rotating speed to minimum but not shutting down the machine. The excess gasses the compressor no longer could process were routed to the Low Pressure Flare in order to protect the compressor. The Flare Gas Recovery's Water Seal Drum for the Low Pressure was compromised at the initial onset of this event resulting in flaring. Followup: Notes: Operations began the process of increasing the compressor's speed back to normal. Once returned to normal speed and the water seal at the seal drum was re-established, the flaring of all excess gases stopped. | 481.0 pounds |
| 156589 2014-06-09 | Sulfur Recovery Unit Incinerator (2774-V3) | Cause: On June 9, 2014 the Sour Water Stripper (SWS) Unit experienced unexpected pressure swings and fluctuating rates in its overhead system resulting in reduced unit efficiency in both the 592 Sulfur Recovery Unit (SRU) the Tail Gas Treater Unit (TGT) subsequently causing an increase in sulfur dioxide (SO2) emissions at the TGT's incinerator (591-D-21X) based upon the stack So2 CEMs monitor.
Preliminary information from the investigation indicated an unexpected SWS feed composition change adversely impacted SRU and TGT operation resulting in elevated SO2 emissions at the TGT's incinerator. Sour water production from various refinery units were reduced in order to stabilize SWS operations and improve sulfur conversion rates at the SRU, which improved SO2 emissions at the incinerator.
A Root Cause Analysis (RCA) investigation was completed and revealed that an unexpected slug of hydrocarbon and hydrocarbon particulate in the sour water feed to the Sour Water Stripper (SWS) Unit. This hydrocarbon was unexpectedly trapped in the feed line between T-101 and the SWS Unit and was released as Tank-101's feed valve was opened during the initial steps of the sour water tank swap. This hydrocarbon contamination resulted in unstable SWS overhead operations that produced pressure and flow swings which further deteriorated proper sulfur recovery at the 592 SRU Unit. Loss of proper sulfur recovery at the SRU Unit resulted in H2S breakthrough at the Tail Gas Treater (TGT) and burning of this H2S in the SRU Incinerator stack causing So2 emissions to spike.
As part of determining all contributing causes to this incident, further investigation revealed that the preparations for using Tank-101 for use as the alternative sour water tank may have contributed to the event. It is suspected that the required flushing of the alternative sour water feed tank's line in preparation for use may have unexpectedly trapped a slug of hydrocarbon in the flush piping.
Another contributing factor to the incident was the fact that there was no available sampling point in the flush circuit which would have allowed confirmation of good hydrocarbon separation from the sour water as well as no hydrocarbon particulate. Followup: Yes Notes: Immediate corrective action: Immediately implemented sour gas shedding by reducing rates from refinery units that produce sour water. SRU operations were stabilized and incinerator emissions were reduced. A Root Cause Analysis (RCA) identified the following measures to prevent recurrence: 1) Improve sour water line flushing procedure to ensure optimum sour water quality and to minimize feed dead legs in the lines that can trap hydrocarbon and hydrocarbon containments, 2) Evaluate lining up the SWS overhead gases to the Flare Gas Recovery System when swapping sour water feed tanks. | 732.0 pounds |
| 156142 2014-05-21 | SRU Incinerator (591-D-21X) and Low Pressure Flare (308F-D-1) | Cause: Sulfur recovery units 591 and 592 experienced an unexpected operational upset that affected both unit flows and pressures. The sulfur conversion rates of both SRUs dropped off, subsequently overloading the tail gas treater (TGT) unit. The refinery implemented its emergency sulfur shedding procedures. The shedding of the refinery acid gas producers allowed the shutdown of SRU Unit 591.
With SRU 591 shut down, the TGT unit tripped offline unexpectedly due to erratic pressure and flow swings. SRU 592 remained in operation, running at reduced rates. Its gases were routed to the SRU incinerator (591-D-21X). Higher-than-normal incinerator temperatures created safety concerns; therefore, the refinery shut down SRU 592 for a brief period of time and flared the remaining acid gas to the Low Pressure Flare (308F-D-1). Further acid gas shedding was immediately implemented with operational adjustments that included shutting down both of the refinery's diesel hydrotreaters, the delayed coker unit, while cutting the crude unit and FCC unit feed rates to minimum and charging feed stocks to both the crude and FCC units.
When safe operating conditions were re-established at the SRU incinerator, Unit 592 was brought back online at reduced rates, and its tail gases remained routed to the SRU incinerator.
On 5/22, it was determined that the Quench Tower (308-V-31) in the TGT train had unexpected sulfur pluggage, which had to be removed for the TGT to properly function and come back online. A repair plan resolving TGT pluggage was implemented and completed with the TGT resuming normal operations on 5/25.
Continuous air monitoring was conducted at the fenceline throughout the event.
Attached emissions calculations show that 750 pounds of sulfur dioxide were emitted from the SRU incinerator on 5/21, 62,500 pounds from acid gas flaring on 5/21, and 26,425 pounds from the SRU incinerator on 5/25.
A Root Cause Analysis (RCA) investigation was completed and revealed there was an unexpected pluggage in the sulfur product line leading from the SRU 592 Unit to the primary sulfur storage tank. Several days prior to the incident, the primary sulfur storage tank had experienced problems with its pumping system that required several days to repair resulting in higher than normal use of the secondary sulfur storage tank to complete the loading and filling of sulfur trucks. When repairs to the pumping system were completed, the sulfur product piping of the SRU 592 Unit was rerouted from the secondary sulfur storage tank back to the primary sulfur storage tank.
The initial SRU pressure increase coincided with this rerouting and the pluggage in the sulfur product piping led to the gradual buildup of molten sulfur in the condensers, reduced cross sectional area of the flow path and increased operating pressure of the SRU 592 Unit. Many operational changes (such as shifting of acid gas loads as well as sulfur shedding) were attempted to compensate for the pressure rise but were not successful.
In determining all contributing causes to this incident, further investigation revealed that the slow responses to the rapid pressure and air rate changes by the air demand analyzer, the Tail Gas Treater (TGT) hydrogen analyzer, and the main air ratio controller led to out of balance air to gas ratios causing overloading of the TGT Unit, preventing it to convert sulfur dioxide in to hydrogen sulfide. This phenomenon ultimately resulted in elemental sulfur precipitation in the TGTs quench tower, leading to a total shutdown of the TGT until the quench tower could be repaired. Followup: No Notes: Immediate corrective action included implementation of the refinery's sulfur shedding plan reducing the sulfur load to the Sulfur Recovery Units. The sulfur shedding plan is documented in the refinery's Consent Decree required Preventative Maintenance and Operability (PMO) plan. The following corrective actions were identified after a Root Cause Analysis was conducted: 1) Develop methods to detect and identify line pluggage in sulfur product piping systems of the SRU Units 2) Conduct a refresher class with operators regarding operation of all equipment in the sulfur recovery system. Include the lessons learned from this incident as part of this review. Note that two different durations are given for this event. In the attachment, the event was said to have occurred for 88.1 hours. Earlier in the document, the figure is given as 5,870 minutes, which converts to 97.8 hours. | 89,675.0 pounds |
| 153687 2014-02-04 | Amine Feed/Effluent Exchangers bank | Cause: On 2/4/14, the amine stripper vessel experienced an upset involving its Amine Feed/Effluent Exchangers bank; this resulted in an unexpected high level in the stripper's reflux drum causing Rich Amine to contaminate the Lean Amine that circulates to various amine contactors throughout the refinery.
Unable to established proper levels at the amine stripper, vessel stripper efficiencies were minimal which resulted in increased levels of hydrogen sulfide in the Refienry's fuel gas system.
The increased levels of hydrogen sulfide subsequently caused all on-line heaters and one supplemental boiler to exceed for a period of time their permitted sulfur dioxide emissions limits.
A Root Cause Analysis (RCA) investigation was completed and revealed that bolt failures due to amine and sulfide stress cracking in the 591-X-4B exchanger bundle floating head caused rich amine to immediately saturate teh lean amine with hydrogen sulfide inside of the heat exchanger shell. With the amine saturated and unable to absorb hydrogen sulfide at the fuel gas conractors, hydrogen sulfide in fuel gas spiked above exceedance limits. Followup: Yes Notes: Reduced acid gas feed make by immediately implementing the sulfur shedding plan documented in the Refinery's PMO plan (consent decree required) for the remaining Refinery operating units. The following corrective actions were identified: 1) Replace the existing 591-X-4A/B/C floating head bolting with stainless steel bolting material to eliminate sulfide stress cracking 2) Evaluate bolts used in other exchangers to make sure the metallurgy is compatible with the service of the exchanger 3) Identify additional equipment that is susceptible to sulfide stress cracking adn evaluate their bolting material metallurgy | 19,306.0 pounds |
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