Hydrogen and Methane Release from a Refinery Plant
In a petrochemical plant, a gas mixture at 270 bar made of 75% hydrogen (H2) and 25% methane (CH4) leaked through the bottom valve of a dryer of a resin production unit. After detection of the leak, the explosive zone near the equipment was estimated to be 7 m. Hydrogen sulfide (H2S) was detected around the leak. The installation was shutdown and depressurised, a nitrogen injection used to neutralise the gas mixture. The emergency plan was called at 13:35, and terminated at 16:40. The pressure in the dryer had dropped to 34 bar.
Event Date
May 31, 2013
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
valve, dryer, a resin production unit
Storage/Process Medium
Location Type
Location description
Industrial Area
Lessons Learned
Lessons Learned
Unknown
Event Nature
Emergency Action
13:10, The leak is detected, the installation is shut down and depressurised, a nitrogen injection neutralized the gas mixture. 13:35 The operator initiatives the emergency plan 14:00 The operator alerts the prefecture which informs the emergency services and the inspection of classified installations. 14:45 The prefecture decides to close the departmental road located 60 m from the unit accident because of the risk of explosion or fire (type "torch"); the plant staff is confined. The pressure in the dryer drops to 34 bar. 16:00 The staff is de-confined 16:40 the emergency plan is terminated and the Crisis Staff at 17.15 pm. The prefecture broadcasted several press releases during the event.
Release Type
Release Substance
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
ARIA data base
event no. 43855