Hydrogen Release an Explosion in a Refinery
The event occurred in a desulfurisation unit for heavy oil (hydro-cracking, Isomax process). The hydrogen release took place from one of the heat exchanges, after the restart of the unit. The reason for the shutdown was for replacing the catalyst. A metallic ring of 1,42 m diameter previously deformed by during maintenance and by thermal cycling, was projected to more than 100 m distance. The hydrogen and the heavy oil contained in the pipe were expelled and exploded immediately, followed by a general fire on the unit. The accidents caused ten fatalities seven injuries, among the workers which were trying to intervene in the original leak.
Event Date
October 16, 1992
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Cause Comments
The immediate cause was the failure of a metallic component, damaged by maintenance and thermal cycling. Nothing is known on the root cause
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
heat exchanger
Storage/Process Medium
Location Type
Location description
Industrial Area
Pre-event Summary
The event took place when resuming normal operation, restarting after a shutdown to replace the catalyst. During the shutdown, the feed/reactor effluent exchangers (including the failed one) were not opened for inspection.
Lessons Learned
Lessons Learned
Unknown
Event Nature
Emergency Action
Unknown
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Flame Type
Source Category
References
References
Event description in the French database ARIA
https://www.aria.developpement-durable.gouv.fr/accident/1792/
(accessed September 2020)
ICHEME event no. 1091216
ICHEME database available at:
https://www.icheme.org/knowledge/safety-centre/resources/accident-data/
(accessed July 2020)