Electrical heat tracing for hydrogen applications
For greater safety and a reduced risk of explosion
Hydrogen is regarded as the key element of the energy transition and makes it possible to significantly reduce CO₂ emissions in industry and transport. Hydrogen is produced alongside oxygen during the splitting of water. It is therefore a readily available energy carrier derived from renewable energy sources. ‘Green’ hydrogen is produced when water is split into hydrogen and oxygen through electrolysis, using electricity from renewable energy sources such as solar or wind power.
Hydrogen is a colourless, odourless gas with a low density. Furthermore, hydrogen is an extremely flammable gas and, when combined with oxygen (oxyhydrogen), is highly explosive. These properties make the use of Ex-certified electrical equipment absolutely essential wherever hydrogen is produced, transported or stored.
Ex-certified trace heating systems – everything from a single source
Hydrogen is used in both liquid and gaseous forms. In its gaseous state at atmospheric pressure, hydrogen occupies a comparatively large volume. However, in order to transport, store and use hydrogen for various energy applications, it is either compressed – i.e. subjected to high pressure (over 350 bar) – or liquefied. Whilst compressing hydrogen is a viable option for small storage volumes (for example, for use in cars), it is not suitable for large volumes (e.g. storage tanks). In such cases, liquefaction is the method of choice – this involves cooling hydrogen to a very low temperature (approx. -253 °C). As a result, it is extremely cold. Liquid hydrogen has a volume 800 times smaller than gaseous hydrogen, meaning that more hydrogen can be stored in the storage tank. The large tanks or storage vessels are fitted with (vacuum) insulation to minimise energy losses.*1
To protect the storage tank foundations from frost, electric trace heating from eltherm is used. The installation of eltherm heating cables ensures that the temperature can be maintained at a constant level of +5 °C. This prevents frost damage and cracking in
the storage tank foundations.*1 (Brief information on the compression and liquefaction of hydrogen, Scientific Services of the German Bundestag)
Key facts
- Available as area heating or localised heating
- Available as prefabricated units or as bespoke solutions
- ATEX and IECEx certified
- Ex-approved and certified electric trace heating solution
FAQ
As gaseous hydrogen has a large volume due to its low density, it is compressed to a high pressure. This allows more hydrogen to be stored in a tank. To ensure that the storage tanks can withstand the high pressure, a constant temperature must be maintained. This prevents the pressure from expanding. The electric trace heating ensures that the temperature is maintained at a constant level.
Liquid hydrogen has a volume 800 times greater than gaseous hydrogen, meaning that more mass can be stored. Liquid hydrogen is produced by cooling it down to -253 °C, making it extremely cold. To ensure that these low temperatures do not cause damage to the storage tank or the surrounding foundations, an electric trace heating system is used to maintain a constant temperature of approximately 5 °C.