Imperial College London (ICL) researchers have been awarded GBP1m funding to develop a carbon negative cement additive. The funding comes from the Carbon Capture, Usage & Storage (CCUS) Innovation 2.0 competition, part of the Department for Energy Security and Net Zero’s (DESNZ) GBP1bn (US$1.28bn/EUR1.23bn) Net Zero Innovation Portfolio (NZIP).
Imperial researchers are transforming magnesium silicate minerals such as olivine, which are naturally abundant, into a supplementary cementitious material (SCM) while simultaneously capturing CO2 in a form that can be used in a range of sustainable construction products. The project is led by Professor Chris Cheeseman, ICL Department of Civil and Environmental Engineering, who said: “The carbon footprint of cement is currently huge, so combining the production of a cement replacement material with carbon capture is a really innovative approach that has massive potential to decarbonise cement, concrete and therefore construction.”
The new process breaks down olivine into its constituent components of magnesia and silica. The silica can then be used as a SCM in concrete. SCMs are added to concrete to make concrete mixtures more economical, reduce permeability, increase strength, or influence other concrete properties. Since it is almost chemically identical to existing SCMs, the new material could be readily implemented within existing building codes, according to the researchers, and should produce concretes with the desirable strength and durability.
The remaining magnesia could be used to permanently sequester CO2, resulting in magnesium carbonate. This mineral is extremely stable, offering long term carbon storage with no danger of leakage. Other materials such as blocks could be made from the magnesium carbonate, allowing permanent CO2 storage within the built environment.
The GBP986,176.28m government funding will be used to further develop and optimise the silica SCM and magnesium carbonate construction products, subjecting them to comprehensive testing regimes.
