Explosion at the desulphurisation unit of a refinery

Event

Event ID: 743
Quality: 3
Description: The accident started with a leakage of distilled petroleum intermediate and hydrogen in the desulphurization unit of the distilled intermediate. Both substances ignited and exploded, with a later fire, in the form of a pool fire and a jet flame from a pipe.
The initial gravity of the event gave rise to the activation of the External Emergency Plan.
Event Initiating system: Event Initiated By A System Containing Also Hydrogen
Classification of the physical effects: Hydrogen Release and Ignition
Nature of the consequences: Explosion Followed By A Fire
Macro-region: Europe
Country: Spain
Date: 12/10/2002
Main component involved?: Pipe
How was it involved?: Rupture
Initiating cause: Material Degradation (Internal Corrosion / Erosion)
Root causes: System Design Error
Root CAUSE analysis: An investigation was carried out and specifically looked at all modifications, maintenance operations, construction works and inspections performed on the installation. According to both sources (see References), a phenomenon of corrosion and erosion of a pipe due to a bad design of the manifold caused a pipe rupture.

Number of injured persons: 0
Number of fatalities: 0
Post-event summary: About 70 m3 of kerosene and 200 Nm3 hydrogen were involved in the accident, which led to material damage in the affected unit.

Corrective Measures: (1) The design of the manifold was modified to improve flow and reduce corrosion.
(2) The plant emergency plan was also improved, in particularly the communication between the Crisis Unit and the different actors.

Reference & weblink: Event no. 29610 of the French database ARIA (accessed December 2020)
Event description in the European database eMARS (accessed December 2020)