The lime kiln at the Energy & Environmental Research Center in North Dakota stands more than seven stories tall, a hulking piece of industrial plumbing that looks like it belongs in a cement plant. It is, in fact, a testbed for something far more ambitious: turning one of the world’s most carbon-intensive materials into a machine for pulling CO2 out of thin air.
Origen Carbon Solutions, a UK-based startup founded in 2013, has spent over a decade refining its proprietary oxyfuel kiln technology. The goal is simple, if audacious: make lime, a foundational material for steel, construction, and water treatment, with zero process emissions. Then, use the same chemical cycle to capture atmospheric carbon. In January, the company announced the results from that North Dakota demonstration, reporting the kiln consistently achieved greater than 99% conversion of limestone to lime in a CO2-rich environment, exceeding performance targets [World Cement, Jan 2026]. For a company that has long operated in the quiet realm of academic spinouts and pilot projects, it was a crucial, noisy signal of industrial readiness.
The chemistry of turning a problem into a solution
Origen’s bet hinges on the lime cycle, a well-understood chemical reaction. Heating limestone (calcium carbonate) produces quicklime (calcium oxide) and releases pure CO2. In a conventional kiln, that CO2,roughly one ton for every ton of lime,is vented to the atmosphere. Origen’s oxyfuel kiln burns fuel in pure oxygen, creating a stream of exhaust that is almost entirely CO2 and water vapor, which is easily separated. This allows the CO2 from the limestone itself to be captured as a pure, pressurized gas, ready for transport and storage [LinkedIn, retrieved 2024].
The twist is what comes next. The quicklime produced is then "slaked" with water to make hydrated lime. This material is highly reactive with CO2 in the air. Spread it on fields or in simple reactors, and it will naturally re-absorb carbon dioxide over time, reverting back to limestone. It’s a closed-loop, mineral-based form of direct air capture that uses an existing global commodity as its engine [CO2 Value Europe, retrieved 2024].
The core commercial proposition rests on three pillars:
- A drop-in replacement. The technology is designed to be compatible with today’s lime supply chains, aiming to retrofit or replace existing kilns rather than requiring entirely new greenfield plants [LinkedIn, retrieved 2024].
- Dual revenue streams. Origen could sell zero-carbon lime at a premium to industries under decarbonization pressure, while also generating and selling carbon removal credits from the atmospheric re-absorption phase.
- Strategic use. By embedding itself in lime production,a market worth tens of billions annually,it builds a capital-efficient foothold in the larger carbon removal market.
Why Shell and Barclays are writing checks
The $13 million Series A round led by Barclays Climate Ventures in January 2025 wasn’t just about venture capital faith [Origen Carbon, Jan 2025]. It was a vote of confidence from industrial and financial incumbents who see a path to scale. Shell Ventures is also an investor, and Origen is working with the energy giant on its Pelican Direct Air Capture Hub on the Gulf Coast, a project that aims to eventually eliminate around one million tonnes of CO2 annually [Shell Global, retrieved 2026]. Another backer, Mississippi Lime Company, is one of the largest producers in North America, signaling potential customer adoption.
This coalition of investors points to Origen’s pragmatic wedge: it’s not trying to invent a new industry from scratch. It’s trying to decarbonize an old, dirty one, and in doing so, create a massive, distributed carbon removal network. For a bank like Barclays, it’s a bet on financing the retrofit of heavy industry. For Shell, it’s a potential carbon-negative feedstock or offset for hard-to-abate operations.
2018 Seed | Undisclosed |
2023 Seed | 0.142 | M USD
2025 Series A | 13 | M USD
The team bridging academia and heavy industry
Origen’s leadership reflects its dual identity as a deep-tech pioneer and an industrial project developer. Chief Scientist and co-founder Tim Kruger ran the Oxford Geoengineering Programme for over a decade and is a co-author of The Oxford Principles, an early governance framework for climate intervention research [Net Zero Climate, retrieved 2026]. He provides the foundational science and academic credibility.
CEO Ben Riddle-Turner, who joined in 2019, brings the commercial heft. A former investment banker with a background in climate science and geology, he has led the company’s global expansion, fundraising, and partnership efforts [Origen Carbon, retrieved 2026]. His role has been to translate the kiln’s lab potential into contracts and concrete, most notably the partnership with UK lime producer Singleton Birch to build a commercial-scale plant [Invest Humber, retrieved 2026]. The team has grown to between 11 and 50 employees as it moves toward commercialization [Tracxn, Jul 2025].
The road from pilot to plant
The successful North Dakota test de-risks the core technology, but the path to commercial impact is measured in tons of lime and tons of CO2, not lab results. The Singleton Birch project in the UK will be the next critical milestone, proving the technology at a scale relevant to industry. The main construction for that zero-carbon kiln was finished in mid-2022, with the company now focused on commissioning and testing [Invest Humber, retrieved 2026].
The economics of carbon removal are still being written. Origen must prove its process is not only technically sound but also cost-competitive. The capital expenditure for an oxyfuel kiln is higher than a traditional one, and the operational costs of oxygen production add another layer. The business case, therefore, leans heavily on the value of avoided carbon liabilities and sold removal credits.
A back-of-the-envelope calculation illustrates the potential. A single, large traditional lime kiln can emit over 100,000 tonnes of CO2 per year. Origen’s process could turn that same facility into a source of carbon removal credits. If the hydrated lime produced re-absorbs its weight in CO2 over a few years, the net carbon impact swings dramatically negative. The unit economics hinge on the spread between the premium for green lime and the market price for durable carbon removal, a spread that is widening but remains volatile.
The incumbent it must beat
Origen’s most direct competition isn’t another startup; it’s inertia. The global lime industry is fragmented, conservative, and operates on thin margins. Convincing a plant manager to rip out a functioning, depreciated kiln for a new, more complex system is a monumental sales challenge, regardless of the carbon math. The company’s partnership strategy with producers like Singleton Birch and backers like Mississippi Lime is explicitly designed to overcome this by sharing risk and aligning incentives.
Among pure-play carbon removal companies, Heirloom Carbon also uses a mineral-based process, though its approach involves exposing crushed minerals to air in stacked trays. The competitive landscape is less about technological winner-takes-all and more about who can build durable partnerships and drive down costs fastest. Origen’s bet is that by anchoring its technology in an existing, essential industrial process, it can achieve scale and credibility that standalone DAC plants struggle to match.
The company is now fundraising to extend its runway into 2027, a clear signal that the capital required to build its first commercial plants exceeds the Series A round. The next twelve months will be about moving from a validated pilot to a financed, operating facility that produces both lime and verifiable carbon credits. If it can do that, the seven-story kiln in North Dakota will be remembered not as a test, but as the prototype for turning a global industry inside out.
Sources
- [World Cement, Jan 2026] Origen exceeds performance targets for first-of-a-kind zero-emission lime kiln | https://www.worldcement.com/europe-cis/23012024/origen-exceeds-performance-targets-for-first-of-a-kind-zero-emission-lime-kiln/
- [LinkedIn, retrieved 2024] Origen Carbon Solutions Company Page | https://www.linkedin.com/company/origen-carbon-solution
- [CO2 Value Europe, retrieved 2024] Origen Carbon Solutions Profile | https://database.co2value.eu/companies/48
- [Origen Carbon, Jan 2025] Origen secures $13 million Series A to deploy limestone-based direct air capture | https://www.origencarbon.com/news/origen-series-a/
- [Shell Global, retrieved 2026] Pelican Direct Air Capture Hub | https://www.shell.com/what-we-do/carbon-capture-and-storage/direct-air-capture/_jcr_content/root/main/section_1637625762/simple/simple/call_to_action_2133127297/links/item0.stream/1719920419855/3e4c2c7f6c5c2a5b1e2c5f5a8d7b1c2c/pelican-dac-hub-fact-sheet.pdf
- [Net Zero Climate, retrieved 2026] Tim Kruger Profile | https://netzeroclimate.org/who-we-are/people/tim-kruger/
- [Origen Carbon, retrieved 2026] Ben Riddle-Turner Profile | https://www.origencarbon.com/ben-riddle-turner/
- [Invest Humber, retrieved 2026] Singleton Birch and Origen zero-carbon lime kiln project | https://www.investhumber.co.uk/success-stories/singleton-birch-and-origen-zero-carbon-lime-kiln-project
- [Tracxn, Jul 2025] Origen Carbon Solutions Company Profile | https://tracxn.com/d/companies/origencarbonsolutions/__A2ykQyozwIL50DQIEqAG2z0RHGuxgjdLBFqAkjvmk4k