Portfolio Spotlight: ZEN Carbon — Building Africa’s Low-Carbon Future
This series highlights the companies Carbon Drawdown Initiative has invested in.
Turning Concrete Into Climate Storage
Africa stands at the crossroads of two massive forces: a construction boom and a climate crisis.
By 2050, one in four people on Earth will live on this continent. Countries like Kenya are building 250,000 new homes each year to keep pace, yet the main ingredient of that growth, cement, drives nearly 10% of global CO₂ emissions.
ZEN Carbon was founded on a bold belief: Africa can lead the world in transforming concrete from a major emitter into a permanent carbon sink. Their mineralization technology injects captured CO₂ directly into concrete, cutting cement use and emissions while strengthening the material itself.
In doing so, ZEN is helping cities literally build carbon into their foundations.
“We’re not waiting for solutions to come to Africa,” said ZEN Carbon CEO Andy Onyango. “We’re building them here, for us, and fast enough to matter.”
From Fuels to Forever Storage
ZEN Carbon’s story started with a different ambition: converting captured CO₂ into synthetic fuels. It was an early step toward circular carbon use, closing the loop between capture and combustion.
But in the lab, a realization took hold. Even clean fuels eventually end up back in the air. If the goal was true climate permanence, they needed a way to lock carbon away for good.
So, they pivoted. Instead of reusing carbon, they decided to store it inside the very materials shaping Africa’s cities. What they arrived at was a process that mineralizes captured CO₂ directly into concrete, creating stronger, cheaper, and permanently carbon-negative building materials.
This shift positioned ZEN Carbon as one of the first climate tech pioneers turning construction into carbon storage.
What They’re Building
ZEN Carbon’s mineralization technology captures CO₂, sourced from partners like Octavia Carbon’s Direct Air Capture systems, and infuses it into concrete during mixing. The reaction transforms CO₂ into solid carbonates, permanently binding it within the material.
The results:
Up to 10% less cement use, with maintained or improved strength.
Lower production costs for builders.
Permanent carbon storage in infrastructure that will last generations.
The company is now moving from lab-scale proof to pilot-scale demonstration: a real building in Nairobi showcasing Africa’s first low-carbon concrete structure. Each milestone pushes the tech closer to commercial rollout in 2026, paired with a digital MRV platform for verified carbon accounting.
Milestones So Far
Signed MOU with Octavia Carbon to collaborate on CO₂ supply and storage.
Joined the Kenya Green Building Society to influence national policy.
Became part of Carbon Removal Kenya, strengthening local CDR advocacy.
Achieved 5% cement reduction through mineralization without sacrificing strength.
ZEN Carbon is now the first company in the Global South with proven CO₂ mineralization in concrete.
What’s Next
Gen 1 Tech (Q1 2026): Targeting 10% cement reduction with 98% CO₂ mineralization efficiency.
Demo Build (Q4 2025): Kenya’s first low-carbon structure showcasing cost and emissions savings.
Commercial Launch (2026): Releasing mineralized concrete blocks with a digital MRV system for verified carbon accounting.
“Every block we produce brings us closer to a future where Africa builds its growth and stores its carbon—at the same time,” said ZEN Carbon CEO Andy Onyango.
Why It Matters
Cement accounts for roughly 8-10% of global CO₂ emissions, more than the entire aviation industry. Yet it remains the backbone of modern development, especially in rapidly growing economies.
Africa’s urban population is expected to double by mid-century. Every new building, bridge, and road constructed with traditional cement will otherwise add to the global carbon burden.
ZEN Carbon’s work means growth doesn’t have to equal emissions. It’s a model of industrial decarbonization built from the ground up: locally driven, scientifically sound, and designed to scale fast.
In short, it proves that Africa can lead in both climate adaptation and climate innovation.
Why We Back ZEN
At the Carbon Drawdown Initiative, we look for founders who move fast, stay grounded in science, and build where impact matters most.
ZEN Carbon checks every box:
A young, ambitious team turning engineering into action.
A science-first approach proven in pilot results.
A continental vision that aligns with real housing demand and policy momentum.
They’re not waiting for global solutions. Instead, they’re building them, faster than anyone thought possible.
If successful, ZEN Carbon could help turn one of the world’s most carbon-intensive industries into a net carbon sink. That’s the kind of leap the climate movement needs right now.
To learn more, visit: https://www.zencarbon.org/
