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TPC Port Neches Explosions and Fire

Overview

On November 27, 2019, a major loss of containment event occurred at the TPC Group Port Neches Operations facility in Port Neches, Texas, in the butadiene process unit. A dead leg between the Final Fractionator A and the manual isolation valve upstream of an offline pump ruptured. Primarily butadiene was released. The material vaporized and formed a flammable vapor cloud. The cloud ignited moments later and caused multiple fires and explosions. The butadiene unit was completely destroyed. Production ceased indefinitely.

Incident Snapshot

Field Value
Facility / Company TPC Group
Location Port Neches, TX
Incident Date 11/27/2019
Investigation Status The CSB's final report was released on December 19, 2022.
Accident Type Explosion and Fire
Final Report Release Date 12/19/2022

What Happened

  • During the night shift that began on Tuesday, November 26, 2019, the unit was reportedly operating normally.
  • At 12:54 a.m., a loss of containment event occurred. The liquid level in the final fractionator A dropped rapidly from its operating level.
  • The liquid, which was primarily butadiene, emptied from the fractionator in less than a minute.
  • The liquid vaporized upon release and formed a vapor cloud.
  • At 12:56 a.m., the vapor cloud ignited. An explosion occurred and created a pressure wave that heavily damaged the site and caused damage to buildings, including houses offsite.
  • At least two additional explosions occurred following the initial blast.
  • At 2:40 a.m., a cell phone recording captured an additional explosion.
  • That afternoon at 1:48 p.m., another explosion propelled one of the facility’s towers into the air.
  • The tower landed within the confines of the TPC PNO facility.
  • In addition to the propelled tower, four additional towers fell as a result of the blast and/or fires: the final fractionator A, an extractive distillation absorber, an out-of-service water wash tower, and the depentanizer.
  • Flammable process fluid continued to release from damaged equipment, and the fires burned for over a month.
  • At 10:09 a.m. on January 4, 2020, the TPC Incident Command confirmed that all fires were out.

Facility and Process Context

  • TPC Group Port Neches Operations facility.
  • Butadiene unit / South Unit.
  • 1,3-butadiene and raffinate-1 production.
  • Final fractionation phase of the butadiene process.
  • High-purity butadiene service.
  • Dead legs in piping associated with out-of-service equipment.
  • Temporary filters installed on the liquid outlet of the final fractionator B to catch popcorn polymer chunks.
  • The facility was regulated by OSHA Process Safety Management and EPA Risk Management Program requirements.

Consequences

  • Fatalities: 0.
  • Injuries: Two TPC employees and a security contractor were injured. Jefferson County officials reported five additional minor injuries to residents of the community.
  • Environmental release: Approximately 6,000 gallons of liquid, primarily butadiene, were released.
  • Facility damage: The butadiene unit was completely destroyed. The incident caused $450 million in on-site property damage and an additional $153 million in off-site property damage. The blast damaged nearby homes and buildings.
  • Operational impact: Butadiene production operations ceased indefinitely. Smaller fires burned for more than one month while isolation efforts were underway. The facility was transitioned to a "terminal and services" operation.

Key Findings

Immediate Causes

  • A dead leg between the Final Fractionator A and the manual isolation valve upstream of an offline pump ruptured.
  • The release of primarily butadiene vaporized and formed a flammable vapor cloud that ignited moments later.
  • The release location could not be isolated from the rest of the process.

Contributing Factors

  • Failures in dead leg identification and control.
  • The suction piping into the final fractionator A to B transfer pump was open to the process with no flow through it and was therefore a dead leg.
  • Dead legs are known by the industry to promote popcorn polymer formation.
  • Popcorn polymer was known to form in the South Unit before the incident.
  • The final fractionator A to B transfer pump was out of service for at least 82 days before the incident.
  • The butadiene process was not equipped with remotely operated emergency isolation valves (ROVs).
  • Manual and locally controlled emergency block valves were unreliable in this type of catastrophic incident.
  • The dead leg procedure did not identify all potential temporary dead legs within the unit.
  • The filer at the Final Fractionator 1 column started plugging shortly after installation.
  • High oxygen readings were due to water in the analyzers.

Organizational and Systemic Factors

  • TPC Group did not have an effective safety management system in place to identify when a safety-critical procedure could not be conducted as intended, or to identify the associated safety implications when the procedure could not be implemented.
  • The 2016 recommendation to assure flushing of piping associated with out-of-service equipment was never implemented.
  • The 2016 recommendation to develop and implement a process to identify and control dead leg(s) in high-purity butadiene service was not implemented.
  • TPC Group likely maintained paper-based copies of spare pump rotation and level inspection sheets in a building that was destroyed during the incident.
  • Written evidence of the water content was not available because it was maintained in a building that was destroyed during the incident.

Failed Safeguards or Barrier Breakdowns

  • remotely operated emergency isolation valves (ROVs)
  • dead leg procedure
  • manual and locally controlled emergency block valves
  • flushing of piping associated with out-of-service equipment
  • process to identify and control dead leg(s) in high-purity butadiene service
  • electronic recordkeeping for paper-based process performance information
  • recording of Dead Leg Inspection check sheets
  • recording of Spare Pump Rotation check sheets
  • recording of handwritten logs documenting the performance of critical process instrumentation
  • ability to isolate the release location from the rest of the process

Recommendations

  1. 2020-02-I-TX-R1 | Recipient: TPC Group | Status: Closed – Acceptable Action | For all TPC PNO terminal operations in high-purity butadiene service, develop and implement a program to identify and control, or eliminate, dead legs.
  2. 2020-02-I-TX-R2 | Recipient: TPC Group | Status: Closed – Acceptable Action | For all TPC PNO terminal operations, passivate all storage vessels, fixed equipment, and associated piping systems in high-purity butadiene service consistent with industry good practice guidance.
  3. 2020-02-I-TX-R3 | Recipient: TPC Group | Status: Closed – Acceptable Action | At the TPC PNO facility, incorporate the recording of any paper-based process performance information into TPC PNO’s existing electronic records management system so that the information can be reliably retained, retrieved, and analyzed in the event of a catastrophic incident.
  4. 2020-02-I-TX-R4 | Recipient: American Chemistry Council (ACC) | Status: Closed – Acceptable Alternative Action | Revise the Butadiene Product Stewardship Guidance Manual to include guidance on identifying and controlling or eliminating dead legs in high-purity butadiene service, including guidance on dead legs formed when primary or spare pumps are out of service and actions to mitigate, control, and prevent hazardous popcorn polymer buildup in in-process or temporary dead legs.
  5. 2020-02-I-TX-R5 | Recipient: American Chemistry Council (ACC) | Status: Closed – Acceptable Alternative Action | Revise the Butadiene Product Stewardship Guidance Manual to provide guidance on a methodology to help identify what should be considered excessive or dangerous amounts of popcorn polymer in a unit and provide mitigation strategies for popcorn polymer excursions.
  6. 1 | Recipient: The TPC Group | Status: Open | Assess the capability of the HF alkylation unit to remotely isolate inventories in the event of a loss of process containment.
  7. 2 | Recipient: The TPC Group | Status: Open | Develop robust policies to prevent and control popcorn polymer development and growth based on industry guidance.
  8. 3 | Recipient: The TPC Group | Status: Open | Establish processes that require unit shutdowns and popcorn polymer incident investigations after threshold quantities of popcorn polymer are observed within the unit.
  9. 4 | Recipient: The TPC Group | Status: Open | Equip equipment that handles large inventories of flammable or toxic material with remote emergency isolation valves so that hazardous releases can be quickly and remotely stopped from a safe location.

Key Engineering Lessons

  • Dead legs in high-purity butadiene service must be identified and controlled, including temporary dead legs created when pumps are out of service.
  • Out-of-service equipment and associated piping should be flushed and managed so that popcorn polymer does not accumulate to hazardous levels.
  • Remote emergency isolation capability is important where hazardous releases cannot be safely isolated locally during a catastrophic event.
  • Process safety systems must be able to recognize when safety-critical procedures cannot be performed as intended and trigger appropriate safeguards.
  • Paper-based process performance records can be lost in a catastrophic fire. Critical records should be retained in a recoverable system.

Source Notes

  • Primary facts were taken from the final report and factual update, which have source_priority 1 and override lower-priority documents.
  • Recommendation status changes from 2023 and 2024 were used to populate recommendation status and summaries where available.
  • Some OCR-corrupted text in the source extracts was ignored where the intended wording could not be reliably recovered.
  • The final report and factual update contain overlapping but not identical descriptions of the initiating event. The consolidated dataset preserves the higher-authority final report framing while incorporating compatible factual update details.

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