Mujer investigadora en el laboratorio


The ekarrih2 project aims to develop advanced liquid hydrogen carriers and hydrogenation and dehydrogenation technologies associated to them and suitable to transport a high volume of hydrogen over long distances at competitive costs and in a more environmentally sustainable way.

At the end of the project EKARRIH2 will:


DEVELOP at least 2 prototypes of hydrogenation/dehydrogenation carrier reactors at laboratory scale based on one of the following technologies: catalytic reactor (fixed-bed, millichannel or microwave), electrochemical reactor.


This project WILL IMPROVE the scientific, technological and commercial position of the Basque Science and Technology Network and of Basque companies in the hydrogen sector in general, and in green hydrogen transport technology in particular. The lines of research proposed in the project are identified as strategic in the Basque Hydrogen Strategy and the Energibasque Hydrogen Strategy.


When hydrogen is not used at the point of production, a hydrogen distribution and transport infrastructure must be in place. There are different options for transporting hydrogen such as compressed gas (gas pipework, tanker trucks, etc.), liquefied hydrogen (e.g. ships) and liquid hydrogen carriers. The most suitable means of transport is selected depending on the distance and the amount of hydrogen to be transported.

H2 transport costs by distance and volume $/kg, 2019

infografia alcance tecnológico

Compressed H2

Liquid H2


Liquid organic hydrogen carriers

Source: BloombergNEF.

In the event of requiring hydrogen to be transported in large quantities over long distances, liquid hydrogen carriers (such as ammonia, liquid organic hydrogen carriers also known as LOHCs) are a very promising alternative, since under ambient conditions they are in a liquid state and present properties similar to those of fossil fuels (e.g. diesel and gasoline). Thus, the handling and storage of such carriers can be conducted by well-known processes and using the existing oil- and gas-based infrastructure for transporting large amounts of hydrogen.


Liquid organic hydrogen carriers

Liquid Organic Hydrogen carriers (LOHC)

LOHC systems are very promising alternatives for hydrogen absorption (hydrogenation) where renewable energy is abundant and hydrogen release (dehydrogenation) to generate electricity where this is low.

To develop these potential lohc systems, several criteria must be taken into account:

  1. Physical characteristics: melting point, boiling point, thermal stability, viscosity and low vapour pressure for easy transport
  2. Reversible hydrogenation and dehydrogenation reactions
  3. H2 storage capacity
  4. Environmental characteristics: there is a need to develop LOHC systems that produce only benign by-products, such as water, during hydrogenation and dehydrogenation reactions.

The aim of the EKARRIH2 project is to study LOHC systems that meet the defined specifications in terms of high H2 storage capacity, low toxicity, cyclability etc.

Ionic liquids (IL) as H2 carriers

Ionic liquids are salts that melt at a certain temperature before decomposing, generally formed by an organic cation and an inorganic or organic anion, with very interesting properties.

  • Low or no vapour pressure
  • Non-flammability
  • High chemical and thermal resistance
  • High solubility of a broad spectrum of compounds (including gases)
  • Easy functionalisation

However, the use of ILs in the field of hydrogen storage is practically unheard of and therefore provides a good opportunity to extend the field of application of ILs.

In this context, ils can offer several advantages compared to lohcs:

  1. No or low vapour pressure and non-flammability could solve the evaporation problems associated with dehydrogenation/hydrogenation processes while increasing the process safety.
  2. With the correct configuration (cation/anion) ILs can present thermal stabilities above 400°C and H2 compatibility.
  3. Their versatility and generally simple and wide range of functionalisation provides ILs with tailor-made physical-chemical properties.

However, ils have some disadvantages that must be considered such as:

  1. Significant decrease in hydrogen gravimetric capacity due to the normally high molecular weight vs. traditional LOHCs.
  2. High cost of ILs compared to the state-of-the-art LOHC systems available on the market.

Proposed needs and innovations for hydrogen carriers in ekarrih project


Development of safe and efficient LOHCs


Development of ILs with sufficient thermal and chemical stability against hydrogenation and dehydrogenation reactions as an alternative to traditional LOHCs.


High density storage fluids


Hybrid structures obtained by alcohol/silane coupling with storage potential of 6%wt.


Low environmental impact systems


Basic structures of renewable or industrial product sources.




Depending on the technology, the catalytic process can take place in two ways:

  • Homogeneous catalysis in one phase, usually liquid: when the catalyst and reactants are in the same phase.
  • Heterogeneous catalysis: for reactions involving several phases, where the catalyst is usually a solid and the reactants and products are gases or liquids. These types of catalysts are more efficient for these applications, as they have higher thermal stability and easy catalyst recovery.

In the case of reversible organic liquid carriers that undergo heterogeneous catalytic reactions, they are usually in the liquid phase due to their low melting point and high boiling point. These properties contribute to make these types of carriers the most suitable option for transport and storage, and offer the possibility of using current infrastructures.


A few laboratories in the world are currently demonstrating the suitability of atmospheric microwave plasma flares to be used in the extraction of hydrogen from hydrogenated compounds, using laboratory sources of up to 10 kW power. However, the history of plasma flares used for hydrogen production shows industrial applications have expanded over decades.


To date, electrochemical hydrogenation (ECH) and dehydrogenation (ECDH) of organic compounds pathways have not been explored and put into practice in depth, despite the advantages such as selectivity, safety and environmental friendliness that the use of electrochemical processes entails. This scenario is now changing due to the progressive integration of renewable energies, which allow cutting back on electricity costs. In this sense, electrochemistry has the potential of making chemical processes “greener” using renewable energies, such as solar or wind power. The main cornerstone for implementing electrochemical conversion routes is the electrochemical reactor.

In an electrochemical reactor, the key components are the electrodes, where the processes of hydrogenation and dehydrogenation of organic compounds take place. Currently, most of the scientific-technical activities in the field of electrochemical processes for hydrogenation or dehydrogenation of organic compounds are oriented towards synthesising high added-value products or waste recovery.

Expected results

Development of ionic liquids as advanced liquid hydrogen carriers.
Development of several different hydrogenation and dehydrogenation technologies.
Development of key components for said technologies: catalysts, electrodes or membranes.
Comparison of liquid hydrogen carriers with other means to transport.

Main indicators

patent applications
indexed scientific journals
supervised thesis
journals at conferences



The project CONSORTIUM consists of several participants

This project, coordinated by TECNALIA, will involve the participation of six other partners included in the Basque Science, Technology and Innovation Network, namely: CIC ENERGIGUNE, CIDETEC, PETRONOR INNOVATION, TEKNIKER, UPV/EHU and BASQUE ENERGY CLUSTER.

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CIC Energi-gune logo
Petronor logo
Tekniker logo
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