The British company Seratech has developed an innovative cement product using olivine, a mineral with abundant reserves. Traditional cement production emits a significant amount of carbon dioxide, accounting for about 8% of global CO2 emissions. By incorporating new materials and processes, the research team aims to absorb and utilize CO2, potentially reducing the environmental impact of cement production. The findings were published in the latest issue of the "Royal Society Open Science" journal.
Seratech and several other startups are actively exploring new approaches to low-carbon cement production, such as incorporating by-products from the steel industry during production and capturing CO2 released during cement production. Carbon emissions in cement production mainly stem from two processes: heating limestone to produce clinker and burning fossil fuels for heat.
In the recent study, researchers replaced some common clinker with olivine, a mineral abundant in the Earth's mantle found on every continent and one of the few gigaton-scale minerals. Olivine, containing silica, enhances the strength and durability of cement. By utilizing olivine, magnesium sulfate can be extracted to react with CO2, forming minerals that reduce CO2 emissions.
Researchers dissolved powdered olivine in sulfuric acid to extract and separate silica and magnesium sulfate. Subsequently, they allowed CO2 to pass through the magnesium slurry, producing a mineral called nesquehonite. To scale up this process, cement plants will use captured CO2 from emissions sources or the atmosphere to achieve negative carbon emissions throughout the production cycle. Nesquehonite can be recycled for manufacturing bricks and other building materials.
Researchers predict that replacing 35% of ordinary clinker in concrete mixtures with silica generated from this process could result in carbon-neutral cement.
