a gas leakage (approximately 70% hydrogen, 21% nitrogen and the rest carbon monoxide and other impurities) occurred at the connection between a temperature measurement casing and a flange in the carbonization workshop cleaning tower. The leakage was reported to the plant leader, who issued the request to the workers to use iron cards and rubber plates to plug the leak. The operation failed and the leakage continued. At 17:00, at the request of the plant leader, the workers used a tire inner tube to wrap the leak.

A gas release occurred in the building for the recirculation of processes gas. The gas was a mixture of hydrogen and nitrogen. It occurred at the outlet valve, during works aiming to replace it. This caused the creation of an explosive gas mixture and the surrounding spaces. The defective valve has been identified several years before, its poor design and ageing caused the gas leakage. The ignition took place with 9 minutes delay after initial leakage.

The explosion was followed by a fire. Eyewitnesses reported seeing a "huge gush of fire". The local fire and rescue team brought the fire under control.According to the company, the explosion was caused by a problem with a pipe that led to a fire involving a mixture of gases including hydrogen, nitrogen and ammonia. The two injured members of staff were treated for shock.

the fire was detected by an employee during the normal inspection tour, . It was caused by the ignition of a leak of process gas (hydrogen, methane and water vapour) from the reforming furnaces. The plant operator stopped the ammonia unit by manually triggering the safety emergency procedure. The natural gas supply was cut off, and this immediately extinguished the flame.The nitric acid unit was kept running at minimum rate. The hot ammonium nitrate solution and ammonium nitrate units are shut down due to lack of ammonia.

Following a trip caused by the safeguarding of an ammonia production line, the syngas released into the atmosphere and ignited.

The syngas leak (hydrogen + methane) occurred at exit of the ammonia production reactor and led to an explosion followed by a fire.The start point of the sequence of events was the syngas at the reactor outlet reaching an abnormal pressure of 150 bar and a temperature of 300C. This caused a flange seal to move, causing the gases to leak. The accident caused a pressure waves and fire observed on the installations over a distance of 450 metres.

The event occurred on vent stack of an ammonia synthesis unit. The release of the gas was more specifically on the water purge line or the hydraulic guard of the vet stack. The process gas consisting in 75% hydrogen, ignited. The fire could be extinguished the by the emergency decompression of the unit and the automatic shutdown of the synthetic gas turbocharger.

In a fertilizer manufacturing plant, during his inspection round, an operator detected a hydrogen leak at a flange of an exchanger located between the conversion and decarbonisation stages of the ammonia processing unit. He alerted the control room. A steam hose is installed blowing towards the flange to dilute the leak. Explosive gas measurements are taken twice per shift to ensure that the consequences of the leak are under control. The area is placed under surveillance. A few days later, 2 vapour rings were placed around the flange.

The failure of a high pressure hydrogen-based synthetic gas feed line to the ammonia converter produced a sudden explosion followed by a severe fire. One of the operators was fatally injured. The failure of the feed line was characterized by a sudden rupture. There was no leakage prior to rupture. Portions of the piping shattered in a brittle fracture, which was produced due to a severe hydrogen attack. Extensive blisters were observed on the inside surface which failed.The initial crack probably originated at one of two small nozzles provided for temperature measurements.

In a fertiliser plant, an ammonia synthesis unit stopped following the malfunction of an alternator (due to a thunderstorm). The safety features were operating normally, yet the synthesis gas (N2 / H2) emitted into the atmosphere ignited in the chimney (sparked by lightning?). Alerted by the noise and after noticing the flames raging for 15 min, neighbours contacted the fire department. During this time, the facility operator cut the natural gas intake that supplied the unit and secured the installation. Fire-fighter presence was not required at the site.