Barcelona City Council, through its BIT Habitat Foundation, has selected the Biochar Project as one of the two winning solutions of the “21st Century Street Section” initiative to transform the Catalan capital’s pavement into a model of sustainability and circularity.
In the asphalt mixtures planned for sidewalks and roadways, the usual limestone filler will be replaced by biochar produced by Carboliva from olive stone biomass. This substitution allows for a reduction of approximately 76% in CO₂ emissions associated with the manufacturing of the material, while incorporating a renewable carbon sink.
Biochar integrated into asphalt acts as a carbon store and helps the pavement play an active role in mitigating climate change. According to tests conducted by the project team—composed of AMSA, ELSAN, and the Polytechnic University of Catalonia (UPC)—mixtures with biochar maintain performance levels equal to or higher than conventional ones, with better water resistance, greater toughness against cracking, and good performance under temperature changes.
The project has a grant of 90,000 euros to fund the applied research and prototyping phase, which will run until September 2026. The first “urban pilots” using Carboliva biochar will be deployed on actual Barcelona streets during 2027. During that period, results will be monitored to evaluate their scalability to other cities in Spain and Europe.
For Carboliva, the use of its biochar in this project represents a strategic milestone that validates years of research into the recovery of olive grove by-products. “Having the olive stones from our land become a technological material for a city like Barcelona summarizes the potential of the circular economy and Carboliva’s role in the green future of cities,” highlights Álvaro Espuny, CEO of Carboliva.
The company, based in Puente del Obispo (Jaén), collaborates with the Polytechnic University of Catalonia (UPC) and experts such as José Rebollo Pericot in research into the use of biochar to decarbonise construction through two key projects. One is the development of bituminous pavements with a neutral or negative carbon footprint, capable of capturing up to 3 million tonnes of carbon dioxide per year, and the other is the creation of a more sustainable concrete that replaces natural sand with this agricultural by-product.
The “21st Century Street Section” challenge has been jointly promoted by Barcelona City Council, the BIT Habitat Foundation, and the municipal company Barcelona de Infraestructuras Municipales (BIMSA), together with the Barcelona Provincial Council.