The EHU’s research group SUPREN has assessed the social, environmental and economic sustainability of transporting H2 internationally using liquid organic hydrogen carriers (LOHCs)
A study carried out by the EHU-University of the Basque Country concludes that a more sustainable green hydrogen economy requires a combination of technological improvements and policies that guarantee environmental benefits, economic competitiveness and social responsibility. After analysing various configurations of H2 production locations and global LOHC-based transport routes, the team concludes that there is no perfect scenario. However, the results show that LOHC technology has significant potential to play a key role in the global green hydrogen trade in the near future.
Hydrogen (H₂) is emerging as a key alternative energy for decarbonisation, owing to its versatility and potential for application in several sectors. Global demand reached almost 100 million tonnes in 2024, representing an increase of 30% compared to a decade ago, although low-emission H2 still accounts for less than 1% of total production. The demand for green hydrogen (CO2 emissions-free) is expected to increase substantially in the next decades.
The EHU’s SUPREN research group is leading a large-scale European project (UnLOHCked) involving the “social, environmental and economic assessment of large-scale green hydrogen supply chains in Europe”, explains Victoria Laura Barrio, full professor at the EHU and lead researcher of the project. One of the main challenges of these supply chains is how to transport and store the H2: “Hydrogen contains a vast amount of energy. However, being an ultra-light gas, it takes up a massive amount of space, which makes it difficult to transport and store it”, says EHU professor Ion Agirre.
LOHC: liquid storage, a promising solution
Advanced hydrogen storage methods are currently being developed, including liquid organic hydrogen carriers (LOHCs). “These are organic liquids that behave similarly to conventional oils, into which the hydrogen is incorporated using a simple chemical reaction. This makes it easier to store the hydrogen and to transport it using existing oil and gas infrastructure. At the destination, the hydrogen is released from the carrier using a reverse process.” The researchers emphasise the technology’s great potential and foresee its use in the near future.
Currently, several countries are developing future strategies for the production, export, import and consumption of hydrogen. Professor Victoria Laura Barrio explains that “it would make particular sense to bind the hydrogen to the liquid carrier in southern Europe or Africa —in countries where solar energy is highly competitive— or in regions with a high wind energy potential. The hydrogen could then be easily transported in the form of LOHC, using existing fossil fuel infrastructure.”
In this respect, the group’s researcher Irene Rey has carried out a study on the sustainability of this type of international supply chain. “From an environmental, economic and social perspective, we have performed a life cycle assessment of the processes involved in generating green hydrogen, its hydrogenation process in the carrier liquid, its transport to the end consumer, its release and the return of the carrier liquid —explains Rey—, without taking into account the use and final consumption of the H2.” The study contemplated different configurations of producing countries with a high renewable energy potential (e.g. Namibia, Saudi Arabia, Norway and Spain) and consumer countries (e.g. Germany, the Netherlands, Japan and Italy), maritime transport and different types of land distribution. The main new aspect of the study was to include a social risk analysis of these supply chains, “a little-studied aspect up to now.”
Priority should not only be given to economic aspects
The results emphasise the importance of further research into how to improve the efficiency of green hydrogen production and the release of hydrogen from the carrier, as both stages involve high energy consumption. “These stages are the most critical in the supply chain”, say the researchers.
According to Rey, the results show that “there is no perfect scenario with benefits for the three aspects analysed —social, environmental and economic—. A balance should be achieved between these across the entire supply chain, with priority not given only to the economic aspects.” For example, “the production stage, being located in countries with different social, economic, political and institutional conditions, presents a high variation in potential social risks.”
The conclusions of the study provide a springboard for making decisions regarding the design of different routes for the future global green H2 trade. Rey believes that “we must do more than simply reduce carbon emissions and production costs. When designing green hydrogen corridors, we should also consider the geopolitical and social implications. How can a future hydrogen trade be developed without reproducing resource extraction dynamics in the Global South for the benefit of the technological and economic development of the Global North?” A study carried out by the University of the Basque Country (EHU) concludes that a more sustainable green hydrogen economy requires combining technological improvements and policies that guarantee environmental benefits, economic competitiveness and social responsibility.
Hydrogen could account for up to 14% of global final energy consumption by 2050, with an ever-increasing share traded internationally as new value chains emerge. This evolving panorama is likely to reconfigure global energy trade. Regions with abundant renewable energy resources, such as Africa, Latin America, the Middle East and Oceania, are increasingly being considered as potential exporters, while Europe, Japan and South Korea are expected to become key importers.
Additional information
This study is part of the doctoral thesis being carried out by Irene Rey at the Chemical and Environmental Engineering Department of the Bilbao School of Engineering at the University of the Basque Country (EHU). The thesis is directed by Dr. Ion Agirre and Professor Victoria Laura Barrio. The study was carried out in collaboration with the Polytechnic University of Milan, where Rey has completed a postdoctoral research stay.
Bibliographic reference
I. Rey, L. Rigamonti, V.L. Barrio, I. Agirre
Sustainability assessment of international LOHC-based hydrogen supply chains: integration of social into environmental and techno-economic perspectives
Chemical Engineering Journal
DOI: 10.1016/j.cej.2026.178425