Event
- Event ID
- 103
- Quality
- Description
- An explosion, followed by a fire, happened in an oven belonging to the hydro-treatment unit. Following a shutdown, the tube, containing only gaseous products and hydrogen, had been affected by instable flows. In presence of a flows lower than nominal, the tube temperature raised up to its mechanical resistance limit. Under internal pressure, it failed with a longitudinal crack of ca. 750 mm
The unit was shut down and the fire extinguished by itself. - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- Europe
- Country
- France
- Date
- Main component involved?
- Pipe
- How was it involved?
- Rupture & Formation Of A Flammable H2-Hc-Air Mixture
- Initiating cause
- Over-Heating (Wrong Operation)
- Root causes
- Root CAUSE analysis
- The INITIATING CAUSE was the failure of a tube of the oven due to overheating.
The the destabilisation of the operative conditions was due to shortcoming in the capacity to control the operative parameters, also due to lack of effective diagnostics by means of measuring gauges.
Facility
- Application
- Petrochemical Industry
- Sub-application
- hydrotreatment
- Hydrogen supply chain stage
- All components affected
- Hydrotreatment unit
- Location type
- Unknown
- Location description
- Industrial Area
- Operational condition
- Pre-event occurrences
- The oven used for hydrotreatment of complex oils had been shut down 3 hours before.
- Description of the facility/unit/process/substances
- It is probable that the oven affected by the explosion was a heat exchanger used to pre-heat hydrogen and other process gases before entering he hydro-treatment reactor.
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Post-event summary
- As a maintenance was planned in January 2006, the unit will not restart before this date.
- Official legal action
- The unit could not restart before the conclusions of investigation and the subsequent updating of safety measures.
Lesson Learnt
- Corrective Measures
The plant operator:
1) verified the soundness of the range of allowed operative conditions,
2) ensured the correct functioning of the thermocouples measuring the temperature of the tubes,
3) improved the operative procedures, in particular those regulating the transitory phases.
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 (mainly)
- Presumed ignition source
- Not reported
References
- Reference & weblink
Event no. 52706 of the French database ARIA (accessed December 2020)
JRC assessment
- Sources categories
- ARIA
