Small fire in the desulphurisation unit of a refinery

The incident occurred in the new Residue Upgradation Facility unit of the refinery, which converts the heaviest oils from crude oil into high-quality, cleaner fuels such as Euro 6 diesel. The unit was was still under construction. Hydrogen gas leaked from a piping connected to a pressure transmitter of the hydrogen compressor and caught fire due to static charges. The automatic sprinklers brought down the fire immediately, after which fire fighters reached the spot and brought the situation under control. No injury.

H2 compressor

There were no workers at the time of the accident. During working times, 200 workers, inlcuding contractors, would be in the surroundings.

DESCRIPTION OF THE PROCESS In a Residue Upgradation Facility (RUF) process, hydrogen acts as a reagent in hydrocracking and hydrotreating reactions to convert heavy hydrocarbon residues into lighter, higher-value products like gasoline and diesel. Specifically, hydrogen: • Breaks down large molecules: Hydrogen, in conjunction with a catalyst, breaks the strong carbon-carbon bonds in complex, long-chain hydrocarbon molecules, converting them into simpler, shorter-chain molecules. • Removes impurities: Hydrogen reacts with heteroatoms like sulfur and nitrogen in the residue, removing them in the form of hydrogen sulfide (H₂S) and ammonia (NH₃), respectively. • Prevents coke formation: Hydrogen saturates reactive species and inhibits coke formation by hydrogenating coke precursors, which can cause issues in the process. • Increases distillate yields: By upgrading the heavy residue into lighter fractions, hydrogen contributes to maximizing the yield of more valuable products, improving refinery profitability. {https://environmentclearance.nic.in/writereaddata/Online/TOR/31_Aug_2018_1557428738TGB9AH7BriefSummary.pdf]

Automatic sprinklers came into action, followind by the intervention of plant fire brigade and the ocal fire fighters.