Solutions Name
Carbstone
Offer Type
Solution offer
Description
Production of masonry blocks without cement or natural aggregates. The blocks are manufactured using:
- residual mineral materials (previously unused) derived from the processing of steel industry slag;
- biogenic CO2 produced through biomethanation.
The material hardens through the absorption and neutralization of CO₂ during the carbonation reaction, resulting in a negative carbon footprint for the manufactured blocks.
Themes
Sustainable construction and renovation
Geographic zones
Belgium
Who is the solution for?
For all customers, both public and private, since it is affordable and easy to install, the Carbstone block can be laid or bonded in the same way as a traditional block.
Environmental benefit
Thanks to its ability to absorb CO2 and the fact that it does not use cement, the Carbstone solution offers a product that reduces the carbon footprint of construction by neutralizing a significant amount of CO2—just as trees do.
It also makes it possible to recycle industrial waste that was previously unrecyclable.
Environmental impact gain - continued
In terms of natural resources: The solution helps prevent the depletion of primary natural resources (sand, gravel).
In terms of waste: the solution enables the recovery of waste that was previously not recycled (slag).
In terms of GHGs: the solution reduces the carbon footprint of construction. Each block absorbs approximately 1 kg of CO2 and prevents the release of 1 kg of CO2 during cement production.
In terms of energy: The block manufacturing process is energy-efficient because the carbonation reaction itself provides the necessary heat.
Solution type
Product
Solution maturity level
Completed and qualified real system through successful operational missions (TRL 9)
How does the solution work?
The raw material consists, on the one hand, of aggregates of various sizes (Ca(OH)₂), recovered by Orbix from mineral waste generated by the steel industry; and, on the other hand, of biogenic CO₂, which is a byproduct of biomethanation. The block is molded in a press and then stored in an airtight curing chamber where high-concentration CO2 is injected. The hardening process results from a carbonation reaction of the raw material with CO2, producing calcium carbonate (or limestone, CaCO₃) and water, according to the following formula:
Ca(OH)₂ + CO₂ => CaCO₃ + H₂O
Prefer has succeeded in optimizing this natural process by understanding and controlling the reaction parameters to enable industrial-scale production.
The result of this process is a block with a negative carbon footprint that possesses all the characteristics necessary for construction.
The block continues to absorb and remove CO₂ from the atmosphere throughout its entire lifespan.
If applicable, what is the added value compared to conventional solutions?
Carbstone’s new technology—the cement-free block—enables CO2 to be captured and permanently removed, whereas in the conventional process, the cement used produces and releases CO2 into the atmosphere during its manufacture.
This results in a twofold benefit in terms of the carbon footprint: some of the CO2 is absorbed, and some is avoided.
Have you already implemented this solution for an industrial client/a local authority? If so, can you name a client who would be willing to testify about the implementation of your solution?
Yes
Galère S.A. — construction of the Pôle des savoirs (Auditoriums) on behalf of the Province of Liège // Eloy — construction of the Bra-sur-Lienne helicopter emergency medical services center
Has your solution been labeled, certified, a winner of a competition/award, etc.? If so, please specify (e.g., Solar Impulse Foundation label, Greentech award, etc.)
The solution is certified by an ATG (product quality and installation) and an EPD (Environmental Product Declaration, including the product’s life cycle assessment)
Location
Wallonie
