A commercial-scale plant in northern Spain is transforming captured carbon dioxide and industrial waste into low-carbon construction materials, offering a possible model for reducing the construction sector’s dependence on mined resources.
Located at the Port of Bilbao, the AGGREGACO2 project combines captured CO₂ with thermal residues from waste-to-energy facilities to produce manufactured aggregates. The materials can be used in precast products, non-structural concrete, blocks, tiles and infrastructure projects.
Carbon Locked Into Construction Materials
The project uses patented Accelerated Carbonation Technology developed by UK-based O.C.O Technology. The process speeds up the natural reaction in which carbon dioxide becomes permanently stored within minerals.
Instead of taking years, the controlled industrial process takes only minutes. Captured CO₂ is combined with thermal residues that would otherwise require disposal in specialized landfill facilities, producing a stable aggregate that can replace sand, gravel and crushed stone.
Unlike many recycled aggregates, the resulting material does more than reduce the use of virgin resources. It also stores carbon within the finished construction product.
The project is being delivered through Biscay Eco Aggregates, a joint venture involving O.C.O Technology, Spanish energy company Petronor and other Repsol-affiliated partners.
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Plant Could Produce 125,000 Tonnes Annually
Once fully operational, the Bilbao facility is expected to capture up to 7,500 tonnes of CO₂ and process as much as 50,000 tonnes of thermal residues each year.
The plant could produce up to 125,000 tonnes of low-carbon aggregates annually, according to the European Climate, Infrastructure and Environment Executive Agency.
Project documents estimate AGGREGACO2 will avoid approximately 28,364 tonnes of carbon dioxide equivalent during its first 10 years of operation. The project has received €3.17 million through the European Union’s Innovation Fund.
Developers had to adapt technology previously demonstrated in the United Kingdom to local waste streams, regulations and industrial conditions in Spain. The project also required collaboration between the energy, carbon capture, waste management, construction and logistics sectors.
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A Circular Model for Construction
The project’s backers hope the facility will demonstrate that carbon-negative aggregates can compete with conventional construction materials while reducing landfill waste and demand for newly mined resources.
The technology could also be expanded to other European regions and adapted for use in the cement and ceramics industries.
If replicated at a larger scale, the model could help construction companies lower the embodied carbon of buildings and infrastructure while creating a productive use for industrial emissions and waste.
Image from Depositphotos
