#1 Co-Reactive

Mar 25, 2025

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4-min read

👋 Hi, I’m Hugo - founder of VCo2.

Starting today, I’m launching a new format. Each week, I’ll spotlight one promising pre-seed/seed climate tech startup you should keep on your radar.

Today we are talking about a startup that is transforming CO₂ into value.

🧪 Co-reactive - Transforming CO₂into high-performance Supplementary Cementitious Materials (SCM)
🔗 Co-Reactive Project
📌 Germany
🌱 Seed
⚙️ Carbon Capture and Green Materials

Cement production is a massive climate challenge – if it were a country, it’d be the third-largest CO₂ emitter with about 8% of global emissions (Source: Research Gate).

Meanwhile, big construction and tech firms have set net-zero goals, creating urgent demand for cleaner concrete.

Capturing carbon dioxide and mineralizing it into cement ingredients, effectively storing CO₂ inside concrete instead of the atmosphere.

Co-reactive’s product can blend into existing cement and concrete mixes without process overhauls. It claims to reduce concrete cost by 10% while cutting the carbon footprint by 50% at 35% substitution.

In a prototype reactor, the team demonstrated that they can transform captured CO₂ into a fine powder that replaces Portland cement by up to 50%.
Each ton of this material permanently locks away ~330 kg of CO₂ by converting it into stable carbonate minerals, all while boosting strength and durability of cement products.
At 25% substitution it claims to achieve the same compressive strength vs. standard cement.
Co-reactive won RWTH Aachen University’s 2023 Innovation Award for its CO₂ mineralization breakthrough and it recently took first place in Holcim’s Circular Construction accelerator program.

Spin-off from RWTH Aachen University’s renowned engineering labs
CEO Dr. Andreas Bremen holds a PhD in CO2 mineralization
CTO Orlando Kleineberg is the plant engineering guru
They both developed the core CO₂-to-cement technology
CCO Willi Peter brings business expertise from his commercial experience at Microsoft and experience scaling tech ventures.

The market for green cement and low-carbon construction materials is booming, with an estimated $38.5 billion in global demand in 2024, projected to reach ~$68.6 billion by 2030 (source: Green Cement Industry Overview)

Climate regulations are kicking in, for instance: Europe’s Carbon Border Adjustment Mechanism will penalize high-CO₂ cement, pressuring suppliers to clean up (source: Carbon Border Adjustment Mechanism - European Commission)
Developers and builders are seeking sustainable options to meet their own ESG and net-zero commitments, creating a demand for carbon-friendly concrete.

Co-reactive has early traction (awards, accelerator wins, and a convertible round from climate-focused angels) and a path to monetization by selling a value-added material at price parity on top of the carbon credits.
Its carbon-mineralization reactor and proprietary process create a high barrier to entry, and if it succeeds, the impact (both climate and financial) could be substantial.
They will likely start raising a seed round soon.
Questions that remains:
- Can they achieve the same carbon capture efficiency and cement performance at ton-per-hour volumes and at competitive cost?
- Will they be able to sell to the construction industry and get to an adoption rate fast enough to keep up with the rhythm of VC-backed startups?

That’s it for today! I hope you enjoyed this post.

Cheers,
👋 Hugo.