On 24 June 2026, at an event co-hosted with TED at the London Science Museum during London Climate Action Week, Tencent announced the 16 winning teams of CarbonX Program 2.0, a global climate initiative distributing nearly $30m in catalytic funding across four technology tracks. Three of those 16 winners are operating in Kenya — Octavia Carbon and Cella Mineral Storage in the CDR core track, and Flux in the programme’s tailored support tier — a concentration that reflects Kenya’s emergence over the past three years as a testing ground for engineered carbon removal.
The selection came from a pool of 660 applications spanning 54 countries, narrowed first to 50 finalists before a panel of experts settled on 16 winners. Ten of the 16 won places in the programme’s four named technology tracks — carbon dioxide removal, long-duration energy storage, CCUS for the steel industry, and carbon utilisation — each receiving approximately $2m alongside access to Tencent’s technical networks and pilot infrastructure. The remaining six, including Flux, receive tailored support covering measurement, reporting and verification, carbon credit procurement commitments, and green-premium subsidy mechanisms. Tencent confirmed that CDR pilots under the programme will take place in Kenya, with steel CCUS pilots in Serbia and China, and long-duration storage pilots in the Maldives.
Sam Davies, founder of Flux, estimated earlier this year that Kenya now hosts roughly 80% of Africa’s engineered carbon removal startups — a concentration he attributed to what he described as a convergence of favourable geology, a power grid that is over 90% renewable, and a government that has amended its Climate Change Act to provide regulatory clarity for the sector. The three CarbonX winners span different methodologies and sit at different stages of development, but they share the same underlying geography.
Octavia Carbon: direct air capture in the Rift Valley
Octavia Carbon, founded by Martin Freimüller and Duncan Kariuki and headquartered in Nairobi, is the furthest along of the three in terms of deployed infrastructure. It describes itself as the first direct air capture company in the Global South, and operates Project Hummingbird — a modular DAC and geological storage facility in the Central Rift Valley, co-located with Cella’s storage infrastructure near Lake Elementaita.
The technology works by drawing ambient air through a contactor chamber, where CO₂ binds to a solid sorbent material. The system then seals, applies heat and vacuum to release concentrated CO₂, which is compressed and piped to Cella’s injection wells nearby. Each reactor unit — designated the Nelion 1 model — is rated at around 25 tonnes of CO₂ per year. Project Hummingbird is targeting approximately 1,000 net tonnes removed annually by end-2026, through 68 modular units. Octavia has broken ground on a second-generation plant with four DAC modules already commissioned. The company employs over 70 people, almost all based in Kenya.
The energy supply is 100% geothermal, contracted from Mumbi Ltd., a private concession holder in a nearby special economic zone. Octavia has also integrated waste heat from local geothermal plants to reduce the electricity load — an important consideration for a technology that is typically criticised for its energy intensity. Climeworks’ Mammoth plant in Iceland, the world’s largest operational DAC facility, runs at roughly $600–$800 per tonne of CO₂ removed. Octavia’s pitch to investors and credit buyers is that Kenya’s cheaper energy, suitable geology, and lower construction and labour costs can drive that figure down materially, though the company has not published a current cost-per-tonne figure for its own operations.
Octavia holds carbon credit pre-purchase agreements with Carbonfuture, Milkywire’s Climate Transformation Fund, and Terraset, with Reuters previously reporting the total contracted value at around $3m, approximately half of it prepaid.
In response to the CarbonX announcement, Octavia said the funding would accelerate Project Hummingbird and open access to Tencent’s network of corporate and research partners. “We have not just theorized about DAC in Kenya; we have built it, tested it, and proven it works here,” the company said. Its stated immediate priority is converting the CO₂ already removed and stored into verified carbon credits that can be delivered to buyers.
Cella Mineral Storage: making the storage work
Cella Mineral Storage, a New York-based startup founded in 2022 by Corey Pattison and Dr. Claire Nelson, addresses what has historically been the harder half of the carbon removal equation: permanent underground storage. Its technology accelerates CO₂ mineralisation by injecting captured gas into volcanic basalt rock, where it reacts with calcium and magnesium to form stable carbonate minerals. Unlike conventional geological storage, which relies on structural trapping and carries long-term monitoring obligations, mineralisation converts CO₂ into solid rock — a process Cella says is effectively permanent and carries minimal leakage risk.
In May 2026, Cella and Octavia completed a first injection test at the Elementaita site, injecting approximately 460 kilograms of pure-phase CO₂ into a basalt formation at a rate of around nine kilograms per minute, using a water-alternating-gas technique adapted from enhanced oil recovery. The result placed Kenya among a small number of countries — alongside Iceland and the United States — where CO₂ captured from ambient air has been successfully injected underground for permanent storage. Cella’s test well was drilled to approximately 2,800 feet, significantly shallower than most sequestration sites targeting deep saline aquifers, which the company says reduces drilling costs and expands the range of viable storage locations.
Cella’s next steps are a second injection test at the Elementaita site and raising capital to drill a monitoring well. The company is also developing what it describes as a replicable playbook for mineralisation projects in volcanic regions, intended to be applicable across Africa, Asia, and the Americas.
Octavia described the integration lesson from the May test plainly: “Capture and storage cannot be treated as separate problems. In practice, they are deeply interdependent, and getting that integration right requires constant refinement.” The co-location of Octavia’s DAC machines and Cella’s injection wells eliminates the transport costs that would otherwise inflate the economics of the combined system.
Flux: enhanced rock weathering at farm scale
Flux operates a different approach entirely. The Nairobi-based company, founded by Sam Davies, spreads powdered basalt across agricultural land and allows it to weather naturally in contact with rainwater. As the rock dissolves, it draws CO₂ from the atmosphere and converts it into bicarbonates, which are carried by groundwater to rivers and eventually the ocean, where the carbon settles permanently to the seafloor. The process is a direct acceleration of a geological mechanism that occurs without human intervention — Flux’s value is in deploying it at agricultural scale and verifying the CO₂ removal precisely enough to generate carbon credits.
The co-benefit is material: the same rock powder that removes CO₂ also supplies minerals that improve soil health and crop yields. Field trials in western Kenya have shown an average 71% increase in crop yields on participating farms, which Flux provides the rock powder to at no charge. The company’s commercial model rests on selling carbon credits to fund the operation; the agricultural improvement is the mechanism by which it recruits smallholder farmers as partners.
Flux’s first commercial transaction took place in September 2024, when it pre-sold 540 tonnes of CO₂ removal to Milkywire’s Climate Transformation Fund through Kenya’s CYNK carbon platform at $370 per tonne — the first ERW carbon removal credits sold in Africa. The company’s current operations are concentrated in western Kenya and at an 800-acre research farm it is developing. It has signed memoranda of understanding for operations in Nigeria and Cameroon.
In CarbonX 2.0, Flux sits in the tailored support tier rather than a named technology track, meaning its support package centres on MRV assistance and carbon credit procurement commitments rather than a direct grant for pilot infrastructure. The distinction matters: ERW’s verification challenge — demonstrating precisely how much CO₂ a given spreading operation has removed — is the sector’s primary scaling bottleneck, and MRV support addresses that directly.
Three methodologies, one geography
The presence of three Kenya-based winners across different CDR approaches in the same programme points to something beyond individual company success. Kenya’s concentration of carbon removal activity has developed quickly and now spans the spectrum from hardware-intensive direct air capture to field-based enhanced weathering. Tencent’s designation of Kenya as its CDR pilot geography formalises a position the country has been building since Octavia commissioned its first machine in late 2024.
Each of the three approaches carries a different risk and cost profile. DAC, in Octavia’s case, is capital-intensive and energy-dependent but produces verified, measurable removal with a clear underground storage pathway. Cella’s mineralisation technology addresses the storage bottleneck that could constrain the broader DAC sector as it scales. Flux’s ERW is lower-cost and more accessible to deploy but faces greater measurement uncertainty and is at an earlier stage of credit market acceptance.
The $2m per winner in catalytic funding — and the tailored support package for Flux — is unlikely to be the determining factor in whether any of these companies reaches commercial scale. For Octavia and Cella, the significance lies more in the Tencent network access and the formal confirmation of Kenya as a CDR pilot site; for Flux, in the MRV support that directly addresses its verification gap. The harder questions — verified credit issuance at meaningful volume, cost reduction to commercial viability, and securing the follow-on capital needed to build beyond pilot — remain open for all three.
What the CarbonX result does confirm is that the international funding community has moved past the question of whether carbon removal can work in Kenya. The current argument is about pace and price.