"All technologies are on the table": a look at ENGIE R&I's 2025 Emerging Sustainable Technologies report

Every year, ENGIE R&I publishes a report on emerging sustainable technologies. Why did you choose to focus this edition on industry? 

Elodie du Fornel: Industry alone accounts for a third of global greenhouse gas emissions—about 24% from energy use and 5% from industrial processes themselves. That clearly deserves our attention. We focused on heavy industry, not least petrochemicals, cement, and steel. The report is structured around three main pillars: the molecule, the electron, and acceleration levers. 

Why use the lesser-known term “defossilization” of industry, instead of “decarbonization”?

Jan Mertens: Because we’re not aiming to remove all carbon—we’re aiming to eliminate fossil carbon. The energy transition will still require carbon-based molecules to produce materials like cement. So we need sustainable sources of carbon: biomass, captured CO₂, recycled plastics. We call this “sustainable carbon.” 

One chapter of the report is dedicated to the “refinery of the future,” showcasing technologies that replace oil- and gas-derived molecules with identical ones made from non-fossil sources. The goal is to stop adding fossil carbon to the atmosphere. In short, we’re not targeting “zero carbon,” but “carbon neutral.” 

The refinery of the future will replace gas and oil with identical molecules from non-fossil sources.

Today, industry mostly runs on fossil energy. Is it truly possible to replace it? 

Jan Mertens: There are three main levers for achieving carbon neutrality: 

• Energy efficiency: Doing more with less energy. This is already well underway.
• Electrification: Using renewable electricity in industrial processes. Electricity is one of the most mature and cost-effective vectors for integrating renewables (solar, wind, hydro). 
• Use of defossilized molecules, like green hydrogen or biomethane, which are essential for certain applications. 

For temperatures below 200°C, high-temperature heat pumps are being developed. These systems can provide heat very efficiently from electricity. Industries like food processing or pulp and paper will likely adopt them and could phase out the use of molecules entirely. 

However, we don’t yet know if electricity can be effectively used for higher temperatures. And even if we assume the necessary technologies will emerge, two questions remain. Will there be enough renewable electricity, at the gigawatt scale, for ports like Antwerp or Dunkirk?
And will the electric grid be capable of handling such loads? 

Steel production is part of the “hard-to-abate” industries featured in the report.

Can you give an example of a technology highlighted in the report? 

Jan Mertens: Traditionally, industry relies on high temperature and pressure to transform matter. But biology offers another path: bacteria can perform transformations at ambient or moderate temperatures. This opens the door to smaller, decentralized, and less costly facilities. Bioconversion is a very promising area. 

Elodie du Fornel: Indeed, we illustrate this in the report with the BioCat project, which produces renewable methane from CO₂ and hydrogen via biological methanation. We also highlight the Steelanol project, which converts industrial emissions into sustainable ethanol. 

What is the maturity level of the technologies covered in the report? Will they be ready by 2050? 

Jan Mertens: If there’s one takeaway from this report, it’s this: we won’t be able to blame technology. In other words, the solutions already exist—at least at the lab scale. The challenge isn’t to invent them, but to accelerate the deployment of what’s already been discovered. 

Elodie du Fornel: The maturity levels, known as TRLs (Technology Readiness Levels), for the technologies in the report generally range from TRL 3 (lab stage) to TRL 7 (prototype). The key challenge is scaling from R&D to industrial deployment. Public authorities have a crucial role to play. 

Plenty of solutions in the report… What about artificial intelligence? Can it help reduce industrial emissions? 

Elodie du Fornel : Absolutely. AI is a powerful acceleration lever. It automates and optimizes complex processes and enables predictive maintenance, for example. It also supports upskilling and fosters learning organizations. In innovation, for example, new materials can be discovered through generative AI. 

Digital twins, combined with AI, enable predictive maintenance.

Are the technologies you describe adaptable to the European context, or do they imply geopolitical dependencies? 

Jan Mertens: That’s an excellent question. We’ll need large amounts of renewable electricity, which means producing it locally. But we’ll also need to import molecules like hydrogen, ammonia, and renewable hydrocarbons. Even to produce renewable electricity domestically, we still rely—and will continue to rely—on many critical materials for manufacturing solar panels, wind turbines, batteries, and electrolyzers. So, we also need to think about how to secure these metals sustainably, keeping the geopolitical context in mind. 

Green hydrogen is costly, hard to transport, and won’t meet all needs. Is it still worth it? 

Jan Mertens: We believe in hydrogen—not just as a final product, but more often as an intermediary. The goal isn’t to burn it for energy. It’s to use it to produce sustainable hydrocarbons: methanol, methane, ethylene, plastics... 

This report is the result of a major team effort… 

Elodie du Fornel: Yes, it involved over 30 ENGIE experts: from ENGIE Lab CRIGEN, Laborelec, Cylergie, and the R&I HQ teams. We’d like to thank and congratulate all of them for this great collaboration.