SUMMARYThe explosion occurred in a catalyst regenerator of the catalytic cracking unit in a fluidized bed during a technical shutdown. A few seconds later, a second explosion is perceived, it is the pressure wave of the first explosion which reached the site recovery boiler 30 m away and connected to the regenerator by pipe. It left 24 people injured; 8 were hospitalized, including 2 suffering from severe burns.

[NOTE: the sources are not completely clear in describing the system involved in this incident ; the following is the most plausible option according to HIAD validator]The explosion happened in two hydrogen tanks ('receivers') whcih were receiving and storing hydrogen produced by a water electrolyzer via two compressors. The hydrogen was then supplyed to a further non-specified generator. The plant had been shut down on August 24 to 26 and resumed the hydrogen production and storage on August 27.

A mixture of hydrocarbon and hydrogen leaks from hydrogenation unit of a refinery. The cloud explodes. The leak was caused due to corrosion of a carbon steel pipe at a bend, which was one eighth instead of five-eighths of an inch. Apparently, automatic shutdown valves failed to operate. The fire was visible from 32 km away. People in a 5 sq. km area were evacuated. Material damage is significant ($ 78.3 million).

An explosion and fire occurred at a reciprocating recycle hydrogen compressor during commissioning of a new Diesel hydrotreatement Unit. It happened during the reactor pre-sulphidisation step, when the recycle gas contained 9000 ppm of H2S (hydrogen sulfide) and the pressure was at 940 psig (65 bar). The failure of retaining bolts on head-end suction valve unloader of recycle cylinder on compressor allowed release of process gas. Investigations revealed that the bolts failed due to material inappropriate to prevent sulfide stress cracking) and inadequate design for the service.

Fire in an ammonia plantA fire broke out in the hydrogen section of ammonia plant.

An employee was attempting to re-weld a lifting point on a brazing furnace cover. He was using a tungsten inert gas (TIG) welding machine to build up an attachment point on the cover when an explosion occurred. Its force lifted the furnace cover and propelled it against the employee. There were no witnesses to the incident. The furnace had apparently not been evacuated completely of gaseous hydrogen, and this may have triggered the explosion.

The accident occurred in a disposal storage for contaminated waste, consisting in a 65-metre shaft flooded with seawater. At the origin of the explosion was the reaction with water of at least two kilograms of sodium and potassium. They reacted violently with the water, producing hydrogen. The explosion opened the ceiling of the storage. A plume of white smoke blowing out to sea was reported by witness. Probably also an emission of radioactive particles occurred.

An in-tank explosion occurred in a gaseous waste decay tank while the plant was in cold shutdown. The gaseous hydrogen present in the tank formed a flammable mixture and ignited due to air contamination of the inert nitrogen system used to control the hydrogen-oxygen concentrations in the tank. This resulted in a release of about 8.8 curies of noble gases and minor tank damage.Generally, the gas in pressurized water reactor waste gas systems is hydrogen rich and the oxygen concentration must be controlled to prevent flammable gas mixtures.

A leak of a flammable mixture of hydrocarbons and hydrogen from a ruptured pipeline caused an explosion and fire, killing one person and injuring forty six. Investigations into the incident found that emergency procedures were not followed.

A hydrogen gas holder exploded.It is assumed that there was diaphragm leak in the hydrogen-oxygen electrolytic cell used to produce high purity hydrogen for a pharmaceutical hydrogenation.