Coffee grounds used to make stronger concrete: RMIT study on biochar from spent coffee grounds for greener construction

Researchers at RMIT University in Australia have developed a method to turn spent coffee grounds into a biochar that can replace a portion of sand in concrete. The process uses pyrolysis, heating the grounds to over 350 degrees Celsius without oxygen, to create a porous carbon-rich material. Concrete made with this biochar can be up to 30 percent stronger than standard mixes. The innovation addresses two problems at once: the 10 billion kilograms of coffee waste sent to landfills each year, which emits methane and carbon dioxide, and the environmental damage from mining river sand for concrete. The research was published in the Journal of Cleaner Production and is still in early stages, but the team sees potential for scaling up. If commercialized, this could reduce the carbon footprint of the building sector while diverting organic waste from landfills. The next step is testing durability over time and finding cost-effective ways to collect and process coffee grounds at scale.