Industrial decarbonization: how hydrogen and CO₂ turn a challenge into an opportunity

The decarbonization of industry is one of the most complex challenges of the European energy transition. Sectors such as cement, petrochemicals, steel and waste management account for a large share of industrial emissions and still lack simple alternatives to fossil fuels and fossil-based raw materials.  

In Catalonia, these sectors are responsible for around 27% of Catalonia's total emissions, and account for around 38% of Catalan exports. Decarbonizing them is therefore much more than a climate goal: it is a condition for their competitive survival in a European market that already has a date and a price for carbon: the European Climate Law sets climate neutrality for 2050 and a minimum emissions cut of 55% by 2030 compared with 1990 levels. 

Why is it so hard? On one hand, in many industrial processes CO₂ doesn't come only from burning fuel — it is an inevitable result of the chemical reaction itself: electrification alone is not enough; industry needs to comprehensively transform how it sources energy, uses carbon, produces molecules, separates and recovers resources, and designs its processes. On the other, industrial plants are renewed every 30 to 40 years, and many alternative technologies have not yet been proven at industrial scale, as the World Economic Forum points out. 

Decarbonizing versus defossilizing: what's the difference? 

It is worth pausing on two concepts that are often confused. Decarbonizing means reducing the greenhouse gas emissions associated with a process, especially CO₂ emissions.  

Defossilizing goes a step further: it means progressively reducing dependence on oil, gas and coal, both as a source of energy and of raw materials, and replacing them with non-fossil energy and carbon sources. In the chemical industry this distinction is especially important: fossil carbon is not just an energy source, but also the raw material used to make plastics, solvents, fuels and many other chemical products. Defossilizing the chemical industry therefore means changing not only how we source energy, but also where we source carbon from, bringing in alternatives such as captured CO₂, biogenic carbon or recycled raw materials. 

That's why defossilizing the chemical industry is, to a large extent, reinventing it. 

Eurecat contributes its own technology in three major areas: the circular economy of CO₂ and waste, renewable hydrogen production, and direct support to companies.  

Eurecat also leads and drives the ecosystem needed to bring this technology to market. For three years it has coordinated the H2CAT network, Catalonia's innovation ecosystem for renewable hydrogen and circular carbon, today a recognized reference in the sector, with 17 entities, 82 research groups and more than 400 researchers. Through the H2CAT Demo Days and other transfer events it organizes regularly across Catalonia, the network connects solutions born in laboratories with the companies that need them. 

Industrial decarbonization and defossilization cannot be solved with a single technology, but with the integration of different solutions along the entire value chain: from the development of materials and components to their integration into processes, scale-up and validation under industrial conditions. Technologies such as electrification, renewable hydrogen, CO₂ capture and valorization, and material circularity must advance in an integrated way. Our goal is to turn these technologies into robust, scalable and competitive solutions, mature enough for industry to adopt them.

—Miriam Díaz de los Bernardos, director of Eurecat's Chemical Technology Unit

Circular economy of CO2 and waste

At Eurecat we work on technologies that cover the entire circular carbon chain: from designing materials to capture CO₂ to building reactors that turn it into useful products. 

 This approach falls under the concept of Power-to-X, which converts renewable electricity into molecules and high-value products. Through electrolysis, renewable electricity is turned into hydrogen, which can react with captured CO₂ —directly or after converting it into CO— to produce methanol, synthetic fuels and other chemical products. In this way, CO₂ can go from being an emission to becoming a carbon source for new production processes. It doesn't disappear — it circulates: it is captured, transformed and reused. We move from challenge to opportunity.. 

One of the most promising applications of this approach is synthetic fuels, or e-fuels. Produced from renewable hydrogen and captured carbon, they make it possible to store renewable energy in the form of molecules and offer an alternative to fossil fuels that is especially attractive in sectors that are hard to electrify directly, such as aviation or shipping. In certain applications, they can also act as "drop-in" fuels, compatible with existing infrastructure and distribution systems, which can facilitate their gradual integration into the energy system.

The European project SunCoChem is a good example: it has developed a reactor that uses solar energy to capture and convert CO₂ into oxo-chemicals, compounds widely used in the manufacture of plastics and resins, without using any fossil carbon source.  

The THUNDER project, also coordinated by Eurecat, follows a similar approach: it combines the capture and conversion of CO₂ and water in a single reactor to produce e-methanol from renewable energy. At Eurecat we handle catalyst synthesis and the design, assembly, optimization and scale-up of innovative reactors, as well as sustainability assessments to improve the energy efficiency of the processes. 

Renewable hydrogen production 

Renewable hydrogen is a key vector for industrial decarbonization and defossilization. It can partially replace fossil fuels in certain processes, but it can also act as a raw material to produce renewable molecules and fuels, such as methanol or synthetic fuels, especially when combined with captured CO₂. Renewable fuels, biomass and biomethane can complement it in processes that require a lot of heat or are hard to electrify, making use of existing gas infrastructure. 

Producing it, however, is only part of the job: it also needs to be distributed safely and at a competitive cost. Since it is the smallest molecule that exists, hydrogen passes through some plastic materials and embrittles steel, and requires specific containers to withstand high pressure. 

Eurecat works across this entire chain. The H-LEAF project investigates new materials and coatings to manufacture the components of hydrogen-producing equipment in series, and at a lower cost. As part of this, it develops new bipolar plates using technologies such as stamped stainless-steel substrate and 3D printing with recycled titanium powder, as well as advanced protective anti-corrosion coatings.

For its part, the HIDROGENIAI project is developing a prototype, in a laboratory demonstration setting, of new tanks to store hydrogen at 700 bar pressure using more resistant materials.  

Beyond electrolysis, Eurecat is also exploring alternative production routes. The HYIELD project is one example: faced with the 300 million tonnes of waste Europe generates each year, whose energy potential is still underused, the project is developing a demonstration plant at a cement factory to produce hydrogen from waste, aiming to turn this waste into up to 30 million tonnes of green hydrogen. Eurecat is involved by designing, using artificial intelligence, a digital twin of the plant that helps estimate its costs and output.

From the lab to industry: technology scale-up and support for companies 

The challenge of industrial decarbonization is not just proving that a technology works, but making it viable: cutting its cost, improving its efficiency and integrating it into a real plant, with the guarantees industry needs to invest in it. That's why Eurecat supports companies throughout this journey, from the lab to industry. 

 A particularly representative example of this leap from the lab to pilot scale is the collaboration with CIUDEN, the Fundación Ciudad de la Energía. Eurecat has developed two plants that bring Power-to-X technologies to a scale of special industrial relevance: one for producing methanol from green hydrogen and captured CO₂, and a second focused on producing sustainable synthetic aviation fuels (SAF) from renewable hydrogen and syngas. These facilities make it possible to validate not only the catalysts, but also the reactors, process conditions, the integration of the different systems and their behaviour under representative operating conditions.

As part of the Decarbonization Project for Catalonia's Electro-Intensive Industry, Eurecat recently won a tender to design four mobile pilot units for CO₂ capture and utilization, each adapted to a different sector: steelmaking, waste incineration, cement and petrochemicals. 

To help these technologies reach the market, Eurecat has launched the Hydrogen Technologies Laboratory, an infrastructure for testing components of up to 50 kW —electrolyzers, membranes, electrodes—, also available as a service for companies and research centres. 

 As we have seen, industrial decarbonization has no single solution. It requires electrifying wherever possible, replacing fossil-based energy and raw materials, capturing and valorizing CO₂, developing renewable hydrogen, and turning renewable electrons into new molecules and fuels. Eurecat addresses this challenge comprehensively: from developing materials, catalysts and processes to designing and scaling up reactors and pilot plants, validating them under representative conditions and transferring these technologies to industry — supporting companies in their scale-up and coordinating, through the H2CAT network, the Catalan ecosystem that must make this transition possible.