How to handle a hydrogen fire in a hydrogenation unit

Emergency pressure relief: the system is stopped from receiving new hydrogen and oil; nitrogen is introduced to maintain a positive pressure at the ignition point, followed by displacement and gradual isolation.

It depends on the situation; I have only encountered cases of large-scale hydrogen leaks, with no fires occurring. In one instance, it was the hydrogen purge line in a diesel hydrogenation reactor (during normal operation, the line cracked, and we went up there wearing air respirators to cut off the damaged section). In another case, it was the casing of a new hydrogen compressor used in hydrocracking (after ensuring the hydrogen system was airtight, ventilation was stopped, all activities in the vicinity were halted, personnel were evacuated, and after confirming that conditions were normal using hydrogen detectors, the construction team was called in to address the leaks). The gas supply can be turned off as long as backflow is prevented; otherwise, careful handling is required. Fire extinguishing should not be attempted before the gas supply is under control, as this could lead to a massive release of hydrogen. If ignition occurs again, it is generally recommended to isolate the leak site and let the fire burn itself out, while cooling down the surrounding areas.

The one in that position? How high is the pressure? The treatment methods vary slightly depending on the location.

Even the slightest leakage can cause a fire, as the ignition energy required is extremely low; it’s not possible to keep the fire burning. If the gasket fails, it can lead to problems, with a domino effect that may affect other nearby facilities and exacerbate the accident. In such situations, there are two options: if the fire is small, it can be contained on-site; but if the flames are intense, it’s best to stop the machine immediately and relieve pressure.

I have encountered a situation where the dew point welding seam in the recycle hydrogen inlet separator tank failed, causing large amounts of hydrogen to escape along with oil and gas; the noise at the scene was extremely loud. The vehicle stopped immediately to relieve pressure, with fire trucks in the vicinity spraying water for cover.

I experienced one incident where a hydrogen pipeline in the boundary area caught fire due to condensate accumulation. During a dark-check, it was found that the fire had started as a result of welding sparks generated by work being carried out nearby during the day; it was a small blue flame, and it seems to have burned for quite some time. We conduct a dark-check once a week, and no serious consequences resulted from this incident.

I experienced one incident where a hydrogen pipeline in the boundary area caught fire due to condensate accumulation. During a dark-check, it was found that the fire had started as a result of welding sparks generated by work being carried out nearby during the day; it was a small blue flame, and it seems to have burned for quite some time. We conduct a dark-check once a week, and no serious consequences resulted from this incident.

If the temperature, volume, and pressure are not reduced significantly, emergency pressure relief will have to be activated. It’s still nice to see that area on fire; it’s better if it’s in a low-pressure area. In high-pressure areas, it’s usually due to oil and gas leaks, which is very troublesome

The device first releases pressure, using fire-fighting water to cool the area where the fire is occurring, in order to prevent the fire from spreading further and avoiding the risk of an explosion. Cut off the air supply and feed at the location of the fire, while introducing diluted nitrogen until the fire is completely extinguished.

Is there a fire leaking out? Which area?