Coffee ground waste into eco-friendly concrete, slashes CO2 emissions

Australian researchers at the Royal Melbourne Institute of Technology (RMIT) have developed an innovative concrete mix incorporating coffee ground waste transformed into biochar, resulting in a material that is both stronger and more environmentally sustainable than traditional concrete. By converting spent coffee grounds—an abundant waste stream in Australia—into biochar through pyrolysis, the team was able to replace a portion of sand in concrete production. Their experiments demonstrated that substituting 15 percent of sand with coffee biochar increased concrete strength by nearly 30 percent while reducing carbon dioxide emissions by up to 26 percent. Even lower substitution rates of 5 and 10 percent yielded CO2 reductions of 15 and 23 percent, respectively, along with a 31 percent decrease in fossil fuel use and improved impacts on aquatic ecosystems. The process involves heating used coffee grounds to approximately 350 degrees Celsius to produce a stable, carbon-rich charcoal-like material that locks carbon within the concrete matrix. This approach supports circular economy principles by diverting organic waste from land