Energy

Currently, different transport technologies for hydrogen are available. Yet, regarding costs, convenience, and technological readiness, it is essential to understand that the right choice depends on several factors. 

The article below briefly overviews the most discussed technologies involving:

• Compressed hydrogen
• Liquefied hydrogen
• Ammonia
• LOHC

Approaches for Hydrogen Transportation

Compressed Hydrogen 

From a practical perspective, powering heavy-duty vehicles (e.g., buses, trains, and trucks) favors compressed hydrogen, whether at 350 Bar or even up to 700 Bar. The 700 Bar solutions primarily depend on the available gas station infrastructure, which differs from country to country. 

A minimum transport distance of 200-300 km is crucial since batteries are often a more economical solution for shorter distances. 

Compressed hydrogen is also the preferred approach for storing and transporting hydrogen for up to 1000-2000 km. 

Liquefied Hydrogen (LH2)  

By contrast, the use of liquefied hydrogen has not solved the issue of boil-off gas so far. This causes a significant loss of hydrogen over time, making it a rather poor choice for powering vehicles. Hence, the (heavy-duty) mobility sector will also use compressed hydrogen in the near future. 

However, looking at the transport of larger quantities of hydrogen (several tons) and longer distances (> 2000 km), liquefied hydrogen is typically of interest for the maritime sector and the build-up of a global hydrogen infrastructure, where the low energy density of compressed hydrogen makes it simply too expensive to become a viable alternative. 

In particular, the transport of (green) hydrogen from its place of production in areas with low $/kg production costs (e.g., Middle East, Australia) to the regions of consumption (e.g., Europe and other regions with a high density of energy consumption) might, therefore, use liquefied hydrogen. 

Though the energy loss from hydrogen liquefaction, the already mentioned issue around boil-off losses and insulation, and the high material requirements for temperatures below 250° Celsius remain areas for improvement.

Ammonia (NH3)

The technology for synthesizing (green) hydrogen with nitrogen to get (green) ammonia is well known and has been established for over a century. However, the later extraction of the hydrogen from this green ammonia (cracking) has not yet been developed at a smaller scale that would be more compatible e.g. with gas stations. Therefore, a possible mitigation might be to use ammonia directly as fertilizer or fuel and completely avoid hydrogen extraction. 

The transport of ammonia itself is common practice and less demanding than liquefied hydrogen. However, the fact that ammonia is an extremely hazardous substance will make it difficult to store larger amounts in densely populated areas.

LOHC

LOHC (Liquid Organic Hydrogen Carrier) stores the hydrogen in an oil-like substance, which can then be transported at ambient temperatures without additional insulation or problems around toxicity– a significant advantage compared to LH2 and NH3.

However, the energy demand for extracting the hydrogen again out of the oil is enormous. At the same time, the technology has not yet been proven to work on a larger scale, with several tons of hydrogen to be transported over decades (as with NH3 or LH2) to know about the degradation of the oil substance. 

The transport of the “de-loaded” oil (after the hydrogen has been extracted) back to the place of “re-loading” (where produced hydrogen will be stored again in the oil) requires a much more complex infrastructure and a high level of dependency on the supplier of the LOHC chemicals. 

Therefore, LOHC still requires more research and could cover certain niches along the intercontinental sea transport supply chains, where LH2 and NH3 are less convenient. 

This article was contributed by our expert Florian Jais

Frequently Asked Questions Answered by Florian Jais

1. What are the key trends shaping investor sentiment towards hydrogen transport and infrastructure investments, and how are these trends expected to evolve?

Two major aspects here are:

• Price of hydrogen 
• Levelised Costs Of Hydrogen (LCOH). 

In the coming years, with larger production quantities of (green) hydrogen and the respective equipment (electrolyzers, fuel cells, cylinders, etc.), the costs for H2-production will go down, as will the LCOH. 

Therefore, it is now more a question of which of the different transport technologies the majority of the investments will go. 

Larger companies are pushing for LH2 (Linde plc) and ammonia (Air Products) to build global infrastructure while LOHC is still under development. 

2. What are the potential synergies between hydrogen infrastructure development and other renewable energy initiatives?

Hydrogen can serve as a buffer to stabilize the electricity networks. Hence, overcapacity of electricity (e.g., solar power during the day) can be stored as hydrogen and is then released when there is a need to (e.g., at night). 

Even though the energy losses when transforming electric energy into hydrogen and back are valid, it is still better than not having this buffer at all. As a result, the more hydrogen we can produce with a respective infrastructure, the more the usage of renewable energies (solar, wind) will benefit—and vice versa.

3. How does LOHC technology revolutionize the transport and storage of hydrogen compared to traditional methods?

• No toxicity (compared to ammonia)
• Usable at ambient temperature (unlike LH2) and pressure levels (unlike compressed H2). 

Therefore, the already existing infrastructure for transporting oil could be used without major modifications.