Hydrogen Fire in a Solvents Production Plant
The hydrogen jet fire a pipe have been detected by a night operator which was making rounds in a solvent production unit. The unit's emergency response team managed the fire in minutes. Operators stopped the flow of hydrogen by closing a valve. The hydrogen network was purged with nitrogen.The unit has three reactors, out of which only one was in operation at the time of the incident. The gaseous effluents from each of the reactors, mainly consisting of hydrogen, were collected via a network of vents and discharged to the atmosphere via a set of hydraulic valves.On the day of the incident, a section of the workshop was completely emptied for maintenance and inspection. The hydrogen leaving the reactor in operation passed through this section which presented fewer obstacles (all equipment had been purged and valves remained open) than the hydraulic valve set of the vent network. At the outlet of the section, the hydrogen escaped to the atmosphere through a pipe which was not free of impurities. The hydrogen flow brought engulfed solid particles with the consequence electrostatic discharge as a result of their friction against the pipe walls. This ignited the hydrogen. In addition, the pipe had been drained the day before, but the solid particles were not be removed by water.
Event Date
January 1, 2018
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
exhaust pipe, solvent reactors
Storage/Process Medium
Location Type
Location description
Industrial Area
Pre-event Summary
On the day of the incident, a section of the workshop was completely emptied for maintenance and inspection. The hydrogen leaving the reactor in operation passed through this section which presented fewer obstacles (all equipment had been purged and valves remained open) than the hydraulic valve set of the vent network. At the outlet of the section, the hydrogen escaped to the atmosphere through the gutter which was not free of impurities. Hydrogen (minimum ignition energy: 0.017 mJ) resulted in solid particles and, as a result of their friction against the pipe walls, an electrostatic discharge occurred and ignited the hydrogen. In addition, the gutter had been drained the day before, the solid particles transported by hydrogen could not be removed by water.The risk analysis did not predict a return of hydrogen to a section through the vent system.
Lessons Learned
Lessons Learned
The risk analysis did not predict a return of hydrogen to a section through the vent system. Following this accident, the UIC (Union of Chemical Industries) advocates:when multiple sections are connected to common facilities, identify all deviations, and their consequences, that may occur on either side of the element in common. In particular, it is necessary to study the situation where the operating conditions are stable on one side, and on the other hand, the operating conditions are transient, such as stopping and starting equipment;when an incident scenario of this type is identified, modify the operating instructions of the unit to include the closing operation of the corresponding valves.
Event Nature
Emergency Action
The unit's emergency response team managed the fire in minutes. Operators stopped the flow of hydrogen by closing a valve. The hydrogen network was purged with nitrogen.
Release Type
Release Substance
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Flame Type
Source Category
References
References
ARIA data base
event no. 52619