Fire in a fertiliser plant

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.
The nitric acid production unit was restarted in the morning, the ammonium nitrate unit the following day.

The ARIA report does not provide any cause analysis. This incident is very similar to the one described in HIAD event 983, which occurred in the same plant in 2019.

reformer

This incident is very similar to the one described in HIAD event 983, which occurred in the same plant in 2019.

The only consequence was the temporary reduction of the production of ammonium nitrate (H₄NO₃) and fertilisers due to lack of ammonia.

This incident is very similar to the one described in HIAD event 983, which occurred in the same plan in 2019. At that time, the leak had been found on a gasket, and all the gasket of the same furnace were replaced.

The description of the event in ARIA (see references) does not contain enough details to understand incident causes and deduce a lesson learnt. One general observation can be issued: despite the enormous progress achieved in safety records of hydrogen in industrial processes, attention to preventive measures is still required.