Fire in a Diesel Distillation Unit
A jet flame occurred in a diesel distillation unit. It was caused by the release and ignition of hydrogen from the low-pressure (60 bar) section of a the unit. It occurred during maintenance works aiming at replacing the temporary seals with definitive ones, after which the discharge valve would have been re-opened and the compressor re-started. The unit was depressurized and the emergency status was called.
Event Date
May 25, 2007
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The immediate cause was the fact that the discharge valve was not completely closed even though the panel control indicated that it was entirely closed.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
Gasoil distillation unit , seals
Storage/Process Medium
Actual Pressure
60
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
Maintenance works were ongoing on the compressor on recycled gas circuit. Temporary seals had to be replaced by definitive seals.
Consequences
Number of Injured Persons
1
Currency
Lessons Learned
Lessons Learned
Ad corrective measure, the plant operator modified the system controlling the opening of the affected valve during the maintenance works.
Event Nature
Emergency Action
Rescue units were on site but they did not make an attempt to extinguish the fire to avoid the formation of a hydrogen cloud. The affected unit was depressurised. After 50 minute the leak was closed and the fire extinguished. Shortly afterward the alarm was terminated.
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Event 33030 in the French database ARIA
https://www.aria.developpement-durable.gouv.fr/accident/33030/
(accessed October 2020)