Via pipeline, by truck or frozen? How to transport hydrogen

The energy transition towards a hydrogen-based economy requires the creation of an entire logistics chain. From hydrogen production - ultimately from renewable energy sources - to distribution. Hybrid models are also possible, where production from a local electrolyser is supplemented by hydrogen supplied from other sources when needed.

Hydrogen transport methods can be classified by distance or state of aggregation, among other factors. The challenge is that hydrogen in gaseous form has a low energy density.

For its transport or transmission, it is therefore preferable to be compressed, liquefied or combined with other molecules.

In simple terms, the prevailing view is that for the longest intercontinental distances, hydrogen transport by ship in chemical compounds, such as ammonia, is best, for shorter distances (up to 1500 km) pipelines are optimal and for final distribution liquefied or compressed hydrogen will be used.

For distribution over short distances and where moderate amounts of energy are required, hydrogen in the form of compressed gas is used. At 50 bar, a storage density of 4 kg of hydrogen per cubic metre is achieved, while at 700 bar, 40 kg of hydrogen per cubic metre can be compressed. This pressure is standard in passenger cars. In buses, on the other hand, a pressure of 350 bar is used. For example, the Solaris Urbino 12 hydrogen has 5 cylinders with a capacity of 312 litres, which hold 36.8 kg of hydrogen.

When cooled to -253 °C, the hydrogen turns into a liquid. This increases its storage density to around 71 kg per cubic metre. Unfortunately, the cooling process is energy-intensive, which means a loss of 25-35% of energy, so it is a viable solution only for long-distance transport.

The most common means of transporting hydrogen are truck sets with trailers - equipped with containers with bundles of cylinders, tubular tanks or tankers for transporting liquid cryogenic hydrogen. Typically, 300-500 kg of compressed hydrogen gas 500 kg of compressed hydrogen gas (pressure 200-250 bar). Modern tankers can load up to 900 kg of compressed gaseous hydrogen (pressure 500 bar), and tankers up to 3500 kg of liquid hydrogen. Liquid hydrogen can also be transported in containerised tanks on ships, trains and trucks.

According to the International Energy Agency, pipelines are the most optimal method of transporting hydrogen over distances of up to 1500 km. In France, the Netherlands, Germany and Belgium there are pipelines dedicated to this fuel. Adaptation of existing pipelines is also possible, at an estimated cost of only around 15% of the budget needed to build new pipelines. Gas turbines, compressor stations, reservoirs and some types of storage facilities will also need to be upgraded to accommodate higher concentrations of hydrogen (above 5%). According to the Energy Regulatory Office, adding hydrogen is possible in Poland, but the transmission grid operator is still assessing the possibility of mixing hydrogen and its permissible limits.

An alternative solution is to incorporate hydrogen into other molecules, which are easier to transport. The greatest hopes are pinned on ammonia and liquid organic hydrogen carriers (LOHC). However, both options involve energy losses associated with conversion, are inefficient and expensive. However, they may be justified for routes above 1500 km, especially for marine transport.

NRA Survey on Hydrogen, Biomethane, and Related Network Adaptations, Agency for Cooperation of Energy Regulators, Ljubljana 2020.

Ammonia –zero carbonshipping fuel? www.maritimecleantech.no/wp-content/uploads/2020/01/Nov19-Ammonia-fuel-NCE-cleantech.pdf

Norweska Strategia dot. Wodoru www.regjeringen.no/contentassets/8ffd54808d7e42e8bce81340b13b6b7d/regjeringens-hydrogenstrategi.pdf

https://www.solarisbus.com/en/busmania/uitp-global-public-transport-summit-2019-world-premiere-of-solaris-urbino-12-hydrogen-914

Yara, Ammonia – zero carbon shipping fuel? www.maritimecleantech.no/wp-content/uploads/2020/01/Nov19-Ammonia-fuel-NCE-cleantech.pdf

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