The most promising piece of climate hardware in the world might be a seven-story kiln in North Dakota that runs on rocks. Specifically, limestone, the same sedimentary stuff that forms cliffs and cathedrals. For over a decade, Tim Kruger, a geoengineer and Oxford researcher, has been working on a simple, if audacious, premise: what if we could use the planet's most abundant rock to scrub carbon dioxide from its atmosphere, and generate industrial heat in the process? His company, Origen Power, just secured $13 million from Barclays and Shell to find out [PR Newswire, January 2025].
This is not another software play for carbon credits. Origen's bet is physical, chemical, and deeply integrated into the bedrock of heavy industry. The company is developing a limestone-based direct air capture (DAC) system designed to be fuel-flexible and, in its ideal configuration, carbon-negative [Origen Carbon, January 2025]. The recent Series A round, led by Barclays Climate Ventures with participation from Shell Ventures and Exascale Fund, is a vote of confidence in a technology that has moved from Oxford whiteboards to pilot-scale construction [Origen Carbon, January 2025].
The chemistry of abundance
Origen's wedge is the chemistry of calcium carbonate, the primary component of limestone. When heated in a kiln, limestone (CaCO₃) breaks down into lime (CaO) and CO₂. In a conventional cement or lime plant, that CO₂ is a waste stream vented to the atmosphere. Origen's process captures that pure CO₂ stream for sequestration. The novel part is what happens next: the lime is then used to scrub CO₂ directly from the ambient air, re-forming limestone in a closed loop. The company claims this integrated approach can be net carbon-negative, especially if the kiln is powered by renewable energy or waste heat [RSC, October 2025].
- Fuel flexibility. Unlike some DAC approaches that require consistent, high-grade heat or electricity, Origen says its kiln technology can run on a variety of fuels, including renewable power or industrial waste heat. This is a pragmatic concession to real-world energy grids and could lower operating costs [Origen Carbon, January 2025].
- The lime co-product. The process doesn't just capture carbon; it produces lime, a critical material for steelmaking, water treatment, and construction. This creates a potential revenue stream beyond carbon credits, anchoring the economics in a tangible industrial product.
- Patent moat. The company holds a patent for a "carbon negative fuel cell" process that oxidizes carbon monoxide to CO₂ while generating power, illustrating the breadth of its integrated energy-and-capture thinking [Google Patents US20160181639A1, June 2016].
From Oxford theory to Dakota pilot
Kruger, who leads a research group at the University of Oxford focused on greenhouse gas removal, founded Origen in 2013 [GOV.UK, retrieved 2026]. Progress was initially measured in academic papers and small grants, including a £249,000 award from the UK government for an Oxy-Fuelled Flash Calciner project [GOV.UK, retrieved 2026]. The real momentum shift came with physical deployment.
In early 2026, Origen announced it had deployed and tested its first zero-emission lime platform at the Energy & Environmental Research Center (EERC) in Grand Forks, North Dakota, reportedly exceeding its performance targets [S&P Global, January 2026]. This is the core demonstration unit. A larger project at the same site, aiming for 1,000 tonnes of carbon removal per year, is slated to become operational [Origen Carbon, retrieved 2026].
Concurrently, the company is moving into a more advanced commercial phase. In September 2024, Origen signed an agreement to begin engineering for the Pelican Gulf Coast Carbon Removal DAC project, which is projected to remove up to 50,000 tonnes of CO₂ annually [Origen Carbon, September 2024].
| Project | Location | Scale (tonnes CO₂/yr) | Status |
|---|---|---|---|
| Zero-Emission Lime Platform | Grand Forks, ND | Demonstration | Deployed & tested [S&P Global, January 2026] |
| EERC Carbon Removal Demo | Grand Forks, ND | 1,000 | Construction kicked off [Origen Carbon, retrieved 2026] |
| Pelican Gulf Coast DAC | Gulf Coast, USA | 50,000 | Engineering phase [Origen Carbon, September 2024] |
The investor calculus: betting on bedrock
The $13 million Series A is a meaningful raise for a hard-tech company at this stage. The investor lineup is telling: Barclays Climate Ventures represents financial capital looking for climate alpha; Shell Ventures brings deep industrial and energy expertise; Exascale Fund and Elemental Impact add a layer of deep-tech and climate-specific conviction.
Their bet appears to be on a combination of foundational science and pragmatic engineering. Limestone is globally abundant and cheap. The core chemical process is well-understood. The innovation is in system integration, efficiency, and unit economics. For an oil major like Shell, the technology could represent a path to decarbonize not just its own operations but to build a new business line in carbon management and negative emissions.
The company is still lean, with an estimated 14-19 employees [Pitchbook, 2026] [Tracxn, retrieved 2026]. The funding will likely fuel the scaling of its pilot projects and the growth of its engineering team, which includes specialists like Principal CAE Engineer Christine Bertrand, who has been modeling the company's processes since 2019 [LinkedIn, retrieved 2026].
Where the chemistry gets complicated
No path to gigaton-scale carbon removal is simple, and Origen's is paved with hard engineering questions. The primary risk is one of scaling and energy balance. Heating limestone to over 900°C is intensely energy-intensive. While fuel flexibility is an advantage, the carbon math only works if that energy is truly low- or zero-carbon. The economic viability hinges on achieving radically low costs per tonne, a feat that has eluded many DAC pioneers.
Furthermore, the market for the lime co-product, while large, is also competitive and price-sensitive. Origen must prove its lime can be produced at a cost that competes with conventional, emissions-intensive production. Finally, the company is entering a field with well-funded and technically sophisticated competitors, from Climeworks' solid sorbent systems to Heirloom's accelerated weathering approaches.
Origen's answer to these challenges is its integrated, closed-loop design. By tying carbon removal to a valuable industrial product and designing for flexible energy inputs, it hopes to build a system that pays for itself faster than pure DAC plays. The success of the North Dakota pilot and the progression of the Pelican Gulf Coast project over the next 12-18 months will be the definitive test of that thesis.
On the back of an envelope, the ambition comes into focus. The Pelican project target of 50,000 tonnes per year is about the annual emissions of 11,000 gasoline-powered cars. If Origen can build ten such facilities, that's half a million tonnes. The gigaton scale it envisions would require twenty thousand of them. The energy required would be staggering, on the order of multiple nuclear power plants dedicated solely to heating rock. That's the magnitude of the problem. For now, Origen's job is to prove the unit economics in North Dakota work well enough to build the second plant, and then the third. Its incumbent isn't another DAC startup; it's the global cement industry, which has been turning limestone into CO₂ for centuries without paying for the cleanup. To win, Origen must show it can do the same thing, but backwards, and for less.
Sources
- [PR Newswire, January 2025] Origen secures $13 million Series A to deploy limestone-based direct air capture technology | https://www.prnewswire.com/news-releases/origen-secures-13-million-series-a-to-deploy-limestone-based-direct-air-capture-technology-302352613.html
- [Origen Carbon, January 2025] Origen secures $13 million Series A to deploy limestone-based direct air capture technology | https://www.origencarbon.com/news/origen-series-a/
- [GOV.UK, retrieved 2026] ORIGEN POWER LTD overview | https://find-and-update.company-information.service.gov.uk/company/08580554
- [S&P Global, January 2026] Origen deploys first zero-emission lime platform, exceeding targets | https://www.spglobal.com/energy/en/news-research/latest-news/fertilizers/012626-origen-deploys-first-zero-emission-lime-platform-exceeding-targets
- [Origen Carbon, retrieved 2026] EERC project update | https://www.origencarbon.com/
- [Origen Carbon, September 2024] Pelican Gulf Coast Carbon Removal DAC project agreement | https://www.origencarbon.com/
- [RSC, October 2025] Article on Origen's fuel-flexible kiln | https://www.rsc.org/
- [Google Patents US20160181639A1, June 2016] Patent for carbon-negative fuel cell process | https://patents.google.com/patent/US20160181639A1/en
- [Pitchbook, 2026] Origen 2026 Company Profile | https://pitchbook.com/profiles/company/183373-03
- [Tracxn, retrieved 2026] Origen Power - Company Profile | https://tracxn.com/d/companies/origenpower/__LTDBvvc6Y_LmIDoCC403hek4hbpcmgtvqaqqxrBdB3c
- [LinkedIn, retrieved 2026] Christine Bertrand profile | https://uk.linkedin.com/
- [GOV.UK, retrieved 2026] UK government CCUD program award details | https://www.gov.uk/