In a polyethylene manufacturing plant, the explosion of a flammable cloud (isobutane, ethylene, hexane and hydrogen) escaped from a reactor during maintenance caused 23 fatalities and 314 injured workers. The explosion is equivalent to that of 2.4 t TNT and comparable to an earthquake of 3.5 on the Richter scale.The main explosion was followed by multiple other explosions (including those of 2 isobutane tanks) and fires which will only be under control after 10 hrs of emergency response.

The fire occurred in the hydrogen treatement unit of hydrodesulfurisation plant.

Hydrogen release and explosion due to a leak in a high pressure hydrogen storage tank, during first start-up of plant.

The methanation reactor vessel was found to be deformed and had a 3-4 inch rupture at a position corresponding to the top of the catalyst bed. It is though that the incident was caused by ethylene entering the reactor. The ethylene reacted with hydrogen on the nickel catalyst, resulting in a very rapid release of energy. The corresponding temperature rise was sufficient to cause a ductile failure of the vessel.The proposed mechanism for the reaction is that ethylene vapour entered the methanation reactor via the cold box where there was a low pressure/high temperature following the trip.

A leak and fire occurred in a hydrogen compression section of a hydrocracker.

The explosion occurred in the ammonia/hydrogen separator of the ammonia reactor due to metallurgical problem.

A pipe failed, probably due to material failure, and the plant was automatically put in hot stand-by (feed and energy supply automatically cut out). The plant was gradually cooled down. After about half an hour, for reasons not yet clarified, a fire started at the outlet of the alkylation reactor. The fire was extinguished by intervention of the operators, plant fire brigade and local fire brigade. The fire water was collected in a basin and disposed of after treatment in the biological waste water treatment plant of the establishment.

A hydrogen leak occurred from a low temperature valve on an acetic acid plant. The leak ignited and the resulting fire burned for about an hour. There was considerable media attention, particularly from local radio. It was surmised that deterioration of the valves may have taken place shortly before the incident.

The event affected the hydrocracker unit. A sudden release into a cracker compressor flare header destroyed a safety relief valve and damaged a sight glass on a liquid collection pot. As a consequence, release of hydrogen rich vapour to atmosphere occurred, necessitating a shut down of the iso-cracker.The damage was limited to that previously described, and there were no injuries. The cracker was returned to service four days later.

Hydrogen enrichment of the gaseous phase in a rail tanker initiated an exothermic reaction between hydrogen and chlorine which in turn triggered fire of iron chloride.