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

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