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Clean Hydrogen Partnership

Small fire in the desulphurisation unit of a refinery

Event

Event ID
1228
Quality
Description

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.

Event Initiating system
Classification of the physical effects
Hydrogen Release and Ignition
Nature of the consequences
fire
Macro-region
Asia
Country
India
Date
Component involved
compressor / booster / pump (pipe)
Failure mode
rupture & ignition
Initiating cause
material degradation (generic)
Root causes
Unknown
Date entry in HIAD
31/10/2025

Facility

Application
Petrochemical industry
Sub-application
Hydrodesulphurisation process
Hydrogen supply chain stage
All components affected

pressure gauge, piping

Process temperature range [C]
ambient temperature (-50°C to +50°C)
Location type
Unknown
Location
populated area
Operational condition
Pre-event occurrences

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 facility/unit/process/substances

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]

Emergency & Consequences

Number of fatalities
0
Number of injured persons
0
Emergency action

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

In-depth data

Release type
gas
Involved substances (% vol)
H2 100%
Release temperature [°C]
25
Probable IGNITION SOURCE

References

Sources categories
News
Reference & weblink

Deccan Cronicle new of 19 Septemebr 2025
https://www.deccanchronicle.com/southern-states/andhra-pradesh/hydrogen…
(accessed November 2025)