Using coffee grounds to produce concrete.

Researchers at RMIT University in Melbourne, Australia, have heated coffee waste without oxygen (a process called pyrolysis) to create biochar that can replace up to 15% of the sand used in concrete mixing. Lead researcher Rajeev Roychand said that incorporating biochar into concrete mixing would increase concrete strength by 30% and reduce the amount of cement needed by 10%.

Concrete containing biochar made from coffee grounds. Photo: RMIT University.

Millions of tons of used coffee grounds are discarded globally, and most end up in landfills, where they release methane gas upon decomposition. Roychand stated that, globally, biochar from coffee waste could replace up to 90 million tons of concrete mix sand. According to the United Nations, concrete production, which involves mixing sand, gravel, cement, and water, is a major contributor to greenhouse gas emissions, accounting for approximately 7% of global emissions. A 2022 UN report also indicated that around 50 billion tons of sand are excavated annually, primarily for use in concrete. Sand mining is often environmentally damaging and contributes to increasing supply shortages.

MINH CHAU

Source: https://www.sggp.org.vn/dung-ba-ca-phe-de-san-xuat-be-tong-post741347.html