Turning concrete into carbon sinks

Could these biochar-based materials help create a greener built environment?

Spotted: As countries around the world struggle to reduce their emissions at the speed needed to avoid catastrophic global warming, carbon dioxide removal (CDR) technologies will likely need to step in to compensate. This is especially the case for high-polluting industries like building and construction, which is responsible for around 40 per cent of the world’s carbon emissions and needs to make serious changes to meet net-zero targets. Startup ecoLocked may have a solution.

The Berlin-based company produces CO2-negative biochar-based additives and admixes for concrete that can help the construction industry slash the carbon footprint of their building materials without compromising on performance. According to the company, the volume of concrete used around the world already has the potential to store four gigatonnes of CO2 every year – and as concrete demand is expected to double by 2060, the carbon-capturing potential of our built environment will grow too.

Instead of allowing biomass residues to decompose and release CO2, it gets heated in the absence of oxygen in a pyrolysis plant to produce biochar, effectively locking the carbon inside. By incorporating biochar into concrete mixes, ecoLocked can turn concrete products and buildings into permanent carbon sinks, where sequestered CO2 is safely stored for millennia.

The startup’s first product is called eLM Zero, which is a biochar-based admix material that allows concrete producers to “inset” the carbon emissions generated by other ingredients (like cement) in the product’s value chain. It partially replaces cement and aggregates, reducing the CO2 footprint of concrete and compensating for other residual emissions. Plus, eLM Zero can be integrated with concrete manufacturers’ existing processes without the need for costly retrofits.

Beyond focusing on supplying eLM Zero to customers, ecoLocked also plans to broaden its product catalogue and expand internationally, with a focus on emerging markets where waste biomass is abundant and there’s a growing demand for green construction. ecoLocked shared with Springwise that the goal is to “enable a cumulative total CO2 impact of one gigatonne until 2040.”

Written By: Matilda Cox