Fire in a Chemical Plant
Hydrogen and butyl acetate released and caught fire on the vent of a hydrogenation reactor, part of a dyes manufacturing plant. The pressure inside the reactor increased due to excess hydrogen resulting from a faulty pressure measurement, till a safety valve opened and released the gas: the event took place on the roof, the roof vent was equipped with a flame arrestor. The wrong pressure reading was caused by the clogging of the connection used for the pressure measure. The rectors hydrogen supply and the injection of nitrogen in the installation were stopped. The Classified Installations Inspectorate performed an investigation.
Event Date
April 12, 2002
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Cause Comments
The immediate cause was due to the fact that the pressure gauge inside the reactor was not working well due to clogging of a connector.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
hydrogenation reactor
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
The pressure in the reactor was higher than normal, due to a wrong pressure reading.
Consequences
Number of Injured Persons
3
Number of Fatalities
4
Currency
Lessons Learned
Lessons Learned
The operator was required to implement a safety improvement program (not directly related to the cause of specific event, but aiming at improving consequences): 1.technical and organizational measures to prevent such an event from happening in the future, 2.designation of explosive zones around all vents in the building likely to release flammable gases or vapors into the atmosphere and to search for such zones in the sites other installations, 3.verification of the compatibility of the explosion-proof equipment near the vent involved with the hydrogen. Several technical provisions were undertaken before the workshop was restarted: doubling up of safety devices to disconnect the supply of hydrogen in the event of overpressure, improvement of the pressure tapping and implementation of preventive maintenance for this device.
Event Nature
Emergency Action
Feeding of hydrogen and nitrogen was stopped.
Emergency Evaluation
The safety valve worked as designed, releasing the hydrogen to the roof without any furthe consequence.
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Flame Type
Source Category
References
References
Incident firstly reported by ARIA