At a wastewater plant in northern Spain, researchers are testing a ceramic membrane technology that converts biogas into low-carbon hydrogen – offering a glimpse of how Europe could decarbonise hard-to-electrify industries while extracting greater value from waste streams. Yet turning that potential into reality will require substantial investment and the development of real market demand, experts warn.
The renewed instability in the Middle East seen in March, with the closure of the Strait of Hormuz, was yet another painful reminder of how dependent Europe remains on imported hydrocarbons. But it was also indicative of how often energy issues only gain wider attention in the old continent during periods of international uncertainty—mostly regarding fuel prices.
While public debate frequently sees energy through the lens of emissions and climate policy, its role in industrial competitiveness, energy poverty, transport or the growing electricity demands of data centres usually receives far less attention. Indeed, households, heavy industries and even digital infrastructure all depend on stable energy carriers in much the same way.
So, it’s no surprise that many governments are now again pushing for more diversity in the EU energy mix. But a somewhat less-discussed and potentially cleaner option in this context is hydrogen. Well known as the most abundant element in the universe, it can be used to store electricity and power vehicles through fuel cells. Also, since it can deliver high-temperature heat, it is often presented as one of the few potential options for decarbonising sectors that are difficult to electrify.
But as flexible as it may seem, hydrogen is not a fuel in the same way as nuclear energy or renewables are. Instead, it is an energy carrier produced by converting energy from another source. In essence, by using energy to split molecules, such as methane (CH₄) or water, we obtain hydrogen that can later be used in a wide range of contexts, from chemical and heat-intensive industries to aerospace and public transport.
Since the early 2000s, it has been hailed as a game-changer, but hydrogen production and storage also pose challenges. For example, most of it is still produced from natural gas, which emits carbon into the atmosphere. Also, its production often requires large amounts of electricity, raising questions about efficiency and cost. Not to mention that hydrogen itself must usually be compressed or liquefied for transport and storage—again, requiring more energy.
“One of the main drawbacks of traditional hydrogen production is that it loses efficiency across multiple process steps,” explains Dr Christian Kjølseth, technology director at CoorsTek Membrane Sciences. “You reform the gas, shift it, purify it and then mechanically compress it—each stage consumes extra energy. Our approach aims to streamline this by integrating these steps into one process”.
Kjølseth is part of a team of researchers and engineers working on the CARMA-H2 project, an EU-funded initiative aimed at developing new ways to make hydrogen production more efficient and environmentally friendly. CoorsTek, in particular, is developing a new system to extract hydrogen from gas mixtures. The process still relies on conventional hydrogen chemistry, producing hydrogen from methane or biogas, with CO₂ as a byproduct. What differs from classic methods is the way the molecules are separated: through a proton-conducting ceramic membrane that allows only hydrogen to pass when an electric field is applied.
“Our ceramic membranes conduct protons at high temperature,” explains Kjølseth. “When we apply an electric field, the protons move through the membrane, and we collect the hydrogen on the other side.”
By continuously removing hydrogen from the gas mixture, the system alters how the reaction unfolds, shifting the thermodynamic equilibrium. “So in principle, you can recover all the hydrogen that is present in the gas mixture. Then you can also compress that same hydrogen directly since it's an electric chemical compressor as well.” The resulting CO₂ is then capture-ready, and, since it is of biogenic origin, it can also be used to earn carbon credits.
All of this is enabled by a technology largely developed in Europe. CoorsTek Membrane Sciences in Oslo has been the site of much of the work on proton-conducting ceramic membranes over the past several years. In that sense, projects like CARMA-H2 reflect a broader European effort to rethink the interaction between energy and industrial processes. One example of this approach can be seen at the project’s demonstration site in Arazuri, in the Comunidad de Navarra, northern Spain.
“The choice of location is not accidental,” says Nancy Tarjenian Astour, Technological Business Development Manager for Europe at the Industrial Association of Navarra, which coordinates the CARMA-H2 project. "The demonstration site is a wastewater treatment plant that already produces biogas as part of its waste management operations. So, we simply transform that biogas, increasing the purity of the CO₂ and obtaining hydrogen for industrial use. The same CO₂ can then be reused in sectors such as agri-food.”
The region’s industrial profile makes it particularly suited as a testing ground. Navarra ranks second in Spain by share of manufacturing employment. Better yet, 31% of the region’s GDP comes directly from industrial output. All this gives local companies a strong incentive to find ways to decarbonise energy-intensive processes while remaining competitive.
The data also already suggests a strong uptake from the Spanish industry. In 2023, Spain ranked fourth in Europe for hydrogen production output, with facilities operating at roughly 75% utilisation. To put it in perspective, that’s higher than Germany’s own 70%, even though Berlin ranks first in production. This suggests that hydrogen generation in Spain is already closely tied to active industrial demand rather than idle capacity.
“The challenge, as always with emerging technologies, is that while you wait for it to reach market maturity, you also need to mobilise demand and prepare the necessary infrastructure. And this requires substantial investment,” explains Tarjenian Astour. “But it's kind of a balancing act. Too much enthusiasm or too much policy support at an early stage, and you risk a bubble. So, the best course of action is to connect innovation with real demand so that you can build a viable market for the technology over time.”
As that market begins to take shape, the technology must now demonstrate that it can operate reliably at an industrial scale while reducing the production process from six steps to a single integrated system. But if successful, the projects may pave the way to a Europe that is less dependent on imported energy—and greener as well. “There is an opportunity to valorise waste more than we do today, potentially reducing our overall carbon footprint,” explains Kjølseth. “At the end of the day, that’s mainly what we hope to achieve through CARMA-H2.”
Background
CARMA-H2 is a four-year project co-funded by the European Union through the Clean Hydrogen Joint Undertaking. It transforms biogas from organic waste into clean hydrogen and reusable CO₂, supporting local, sustainable energy production.