An explosion and fire occurred at a 3000-gallon (approx. 11400 l) reactor, part of the production process of linear alkyl benzene (LAB), Process materials released from the various vessels and piping fuelled a subsequent fire that took approximately 2 hours to extinguish.As reported by Ali Reza (Ali Reza et al., 2007, see References), before the explosion, the bottom of the reactor was plugged with approximately 180 gallons (approx. 800 l) of a sludge-like mixture of coarse aluminum powder, aluminum chloride and various hydrocarbons.

The incident occurred in the building containing the residues of production. The alarm was given by an employee who heard detonations coming from the building. A few seconds later, the building's fire alarm went off. Following the bursting of a container of sodium residues, a fireproof pallet was consumed without flame. The emergency response team opened the doors of the building to evacuate the smoke and then entered the building. They stopped the burning pallet with a powder extinguisher and performed a flame by means of a thermal camera The intervention is finished before 5 am.

The incident occurred in an electrostatic filtration unit. When flushing with air during the start-up phase of a sulphonation plant, an explosion occurred in the upper partof the electrostatic filtration plant (electrostatic precipitators). The most serious effects of the pressure wave were the violent detachment of the manhole cover of the plant, rupture of two insulating supports and deformation of the gas distributor plate.[DECHEMA incident database, event no. 05/ 2001]

A gaseous mixture of hydrogen (H2), methane (CH4) and ethane (CH3-CH3) at 54 bar was cooled in a heat exchanger upstream of a hydrogen purification system. The accident started with a double explosion followed by a fire.The heater used to regenerate the adsorbent beds of the purification unit had been repaired a few hours earlier, but the automatic heating mode had not been activated upon restart. Therefore, two regeneration cycles had been carried out cold, causing an overload of the adsorber and the fouling of the heat exchanger.

Hydrogen leaked from an analyser and ignited .On-site staff isolate the leak. As the leak was very quickly isolated, the amount of hydrogen released was negligible. Event no. 35501 of the French database ARIA (accessed December 2020) https://www.aria.developpement-durable.gouv.fr/accident/35501/

Explosion in a fine organic chemical plant (Seveso classified )The event occurred during the cleaning of a reactor. At the completion of a batch manufacturing of a soft reducing agent, an operator was rinsing the 3000-litre reactor first with a solvent and then with a water jet . Noticing a smoke release, they informed their team leader, who opened the manhole of the reactor. This action caused a flash type explosion at the reactor entrance. According to the ARIA report (see references), the rinsing water reacted with sodium hydride (NaH) residues on the reactor walls to form hydrogen.

The event occurred in an atmospheric pressure tank storing effluents. The plant was in the production phase. The head of the overfill prevention valve located at the top of the tank was thrown a distance of 77 m. The tanks shell was deformed (curved downward) but not leaking. Employees noted a noise similar to the opening of a valve, and a low-pressure alarm in the tank appeared in the control room, despite the fact that the level and temperature were normal.

The event was initiated by the burst of a rupture disc on a reactor during a hydrogenation process. The hydrogenation reaction occurs under pressure in a tank containing 3,000 l of a mixture of ethanol (a flammable and toxic solvent), red hair dye, a catalyst (palladium on carbon) and hydrogen. As a result of the disk rupture and the following tank decompression, decompression, part of the tank content was expelled and landed on the roof of the building.The emergency action consisted in stopping the supply of hydrogen and to purge the tank with nitrogen.

The fire broke out in the acid etching tank of the ferric chloride manufacturing unit of a SEVESO-classified chemical plant. In this tank, the attack reaction of the iron metal with hydrochloric acid in solution is carried out, which results in ferrous chloride and hydrogen. The hydrogen generated is swept away by a large supply air fan to maintain the gaseous sky of the tank below the LFL. A few days after the accident, the operator opened and analysed the tank to determine the origin of the fire.

In a chemical plant (SEVESO), corrosion on the water side of a cooling exchanger caused water to enter the sulfuric acid and attack the steel in the tank. This reaction produced hydrogen that accumulated in the dome of the tank and caused the explosion.The explosion causes the cover of a 99.2% sulfuric acid tank to open partially. The tank was filled to 300 t of its total 1500 t capacity. The cover opened along the circumference of the tank at the dome / shell fitting. The POI (internal emergency plan) was started.