Reduciner, a Finnish deep tech startup that turns captured industrial carbon dioxide into usable fuel and raw materials, has closed its first funding round and is now preparing to build its first industrial-scale pilot facility. The company was spun out of VTT Technical Research Centre of Finland and is led by CEO and co-founder Johanna Grönroos, who previously held leadership roles at Ernst & Young, Efima, and Lamor Corporation. Its core idea is practical: take CO₂ that industries cannot avoid producing and convert it into something useful.
Heavy industry has a decarbonization problem that cleaner electricity cannot fully solve. For cement, roughly 85% of CO₂ emissions come from the calcination process itself, the chemical reaction that occurs when limestone is heated at extreme temperatures, and that reaction produces CO₂ regardless of how the energy powering it is generated. Steel faces a structurally similar problem. Together, the two industries account for roughly 15 to 19% of global CO₂ emissions, more than aviation and shipping combined. These are the sectors Reduciner is built for.
The company raised EUR 3.6 million in equity from Voima Ventures, Lifeline Ventures, and the Mikko Kodisoja Foundation. VTT contributed an in-kind investment by transferring user rights to the underlying technology and intellectual property to the newly formed company.
Lime is one of the most widely used materials in industrial production, serving as a key input in steelmaking, water treatment, and construction. Producing it requires burning limestone at very high temperatures, a process that releases CO₂ as a direct chemical byproduct, not simply as a consequence of burning fossil fuels for heat. For decades, that CO₂ has been released into the atmosphere because no economically viable use for it existed at industrial scale.
Regulation is tightening across the EU and other major markets, and the demand for sustainable fuels and industrial gases is growing. Those two forces together are creating real commercial incentives for companies that can offer a workable path to lower emissions in heavy industry, without requiring operators to rebuild their entire production infrastructure.
"Reduciner stands out because it is already doing what many industrial climate companies can so far only promise on paper: validating the technology while advancing commercial discussions and solving real customers' problems. For Voima Ventures, that combination matters. When you have breakthrough science, early proof that the solution works, and ongoing negotiations that show clear market pull, you have the foundation of a very compelling company. This is the reason we at Voima Ventures are backing the team." — Pontus Stråhlman, Partner at Voima Ventures.
The capital will go toward building a 1MW industrial-scale pilot facility in Finland. This is the step that moves the technology from laboratory validation into a real production environment. Reduciner plans to run small-scale demonstration installations during 2026 and has set a target of broader international expansion before 2030.
The business model is designed not to depend on subsidies alone. Alongside the synthesis gas it produces, Reduciner's process generates activated carbon as a co-product. Activated carbon is used in water and gas purification, and stricter environmental regulations are expected to push demand for it higher in the coming years. That additional revenue stream improves the overall economics of the process and reduces reliance on policy incentives or fossil fuel price movements.
Hydrogen costs are another factor. Producing synthetic fuels via hydrogen-based methods is expensive and energy-intensive. Reduciner's approach produces carbon monoxide directly, which reduces the amount of hydrogen needed. According to the company, this can lower capital and operating costs for downstream fuel production by an estimated 20 to 30%.
Reduciner's thermochemical process was developed over several years at VTT and has been validated through pilot-scale testing. It uses renewable electricity and biogenic carbon to convert CO₂ into carbon monoxide, which can then be used as a fuel or as a feedstock for producing synthetic fuels and chemicals. Because carbon monoxide is already compatible with existing industrial equipment, adopting the technology does not require plants to replace their machinery.
The three co-founders each bring a different layer of expertise. Grönroos leads the commercial and financial side of the business. CTO Eemeli Tsupari spent his career at VTT focused on industrial electrification and low-carbon process development, and served as project manager on VTT's Decarbonate project. COO Sampsa Vuori has more than 20 years of experience in the steel and chemical industries, with specific work on CO₂ capture and reuse in lime production at a plant in Tornio, Finland.
"Most technologies that seek to replace fossil fuels with more sustainable ones require rebuilding of infrastructure. Reduciner's technology converts CO₂ into CO, which is compatible with existing machinery, allowing the solution to be deployed faster and more cost-efficiently. What makes Reduciner stand out from other deep tech companies aiming to develop sustainable fuel alternatives is that with our process, the sustainability impacts are reached profitably from the very beginning while also unlocking significant market potential." — Johanna Grönroos, CEO and co-founder of Reduciner.
This is Reduciner's first external funding round. Voima Ventures is a Finnish venture capital firm that backs deep tech and science-based companies. Lifeline Ventures is one of Finland's most established early-stage technology investors. The Mikko Kodisoja Foundation also participated. VTT's contribution came in the form of an in-kind transfer of technology rights and intellectual property rather than cash.
"What's rare about Reduciner is how much is already in place at the spin-out stage — advanced commercial discussions, a first deployment model with partners, and a team that spans the full stack from science to finance. We're excited to be part of this from the start." — Juha Lindfors, Managing Partner at Lifeline Ventures.
