Hydrogen safety-
for shipping & offshore

Hydrogen does not impose major new risks compared to ather gases. The trouble spots occur where people are involved in tasks along the hydrogen value chain, from production to use.

Even though specific challenges differ between applications, plant safety is common to all.

Here are some of the risk factors which Dräger explores in projects with customers.

Explosion

Unlike actual explosives, pure hydrogen cannot explose. The risk comes when is hits the air. For hydrogen to cause an explosion, oxygen needs to be present. But if hydrogen is allowed to escape, even a static spark from clothing would be enough to set off an explosion.

Invisible flame

Hydrogen burns with a pale flame that is invisible in daylight. Because it emits little of the infrared radiation that humans perceive as heat, it cannot be sensed as heat. A hydrogen flame does however emit substantial ultraviolet radiation. Special UV detectors are therefore required to alert to the presence of hydrogen flames.

Leaks

Owing to its small molecules and low viscosity hydrogen can leak from pipelines and other structures more easily than denser gases. In fact, when it leaks from a pipe at sufficiently high pressure, hydrogen can even self-ignite. As well as pipelines engineered to hydrogen-ready specifications, regular inspection is imperative to detect leak points at joints and along pipelines. Fixed lead detectors add another layer of safety.

Permeation

Hydrogen can easily permeate materials and in some cases embrittle them. For this reason, stainless steel and composite materials are typically used for storage tanks.

CO alarms

Carbon monoxide (CO) sensors are cross sensitive to hydrogen. If used near possible hydrogen exposure, CO sensors should be compensated for hydrogen so that cross sensitivity and false alarms are reduced to a minimum.

Gas pockets

Like ammonia and methane, hydrogen is less dense than air and forms gas pockets below indoor ceilings when leaking. The presence of hydrogen will not be perceived at ground level, even when dangerous amounts are accumalating beneath the ceiling. When hydrogen and methane are mixed, hydrogen can form gas pockets above methane. Hydrogen detectors are therefore typically placed at the top, with methane detectors below that level.

Odourless and colourless

Hydrogen has no smell and no colour, so is undetecable for humans. With methane, this issue is mitigated by adding odorants, and research is in progress to determine whether this will also be possible with hydrogen. Gas and leak detectors are essential.