Explosion in the Hydrogenation Reactor of a Food Products Plant
Explosion in a food products plant (Seveso classified)The event occurred in the settling cyclone of a hydrogenation reactor of a starch production unit. The process consists in introducing the starch hydrolysate mixture into the reactor with a catalyst (Raney nickel), under agitation and 50 bar of hydrogen at 130C. The reaction lasts three hours, after which hydrogenated mixture is racked and decanted before purification. The explosion occurred during the discharge of the reactor into the settling cyclone. These operations take place 6 to 8 times a year.The ARIA report (see references) does not state with certainty the cause(s), but mentions the opinion of the plant operator, that the explosion was possibly due to the presence of hydrogen in the settling tank. This would be a leak due to a welding defect in part of the reactor containing the gaseous phase.
Event Date
September 18, 2014
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The immediate cause, assuming correct the analysis of the plant operator, was the hydrogen leak from the reactor to the cyclone through a welding degradation.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
starch hydrogenation reactor, settling cyclone
Storage/Process Medium
Actual Pressure
50
Design Pressure
50
Location Type
Location description
Industrial Area
Pre-event Summary
A settling cyclone is a type of dusk collector/removal. (Hydrogenated) starch hydrolysates are mixtures of several sugar alcohols.
Consequences
Number of Injured Persons
3
Currency
Lessons Learned
Lessons Learned
The ARIA report (see references) does not mention improvement actions undertaken after the explosion. Assuming correct the proposed explosion cause, a hydrogen leak via a (growing) welding defect, the most logic lesson learned would be to improve inspection procedures for a better control of welding and assessment of the overall tightness of the hydrogenation reactor.
Event Nature
Emergency Action
Unknown
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Event description in the French database ARIA
https://www.aria.developpement-durable.gouv.fr/accident/45736/
(accessed September 2020)