Imperial researchers have been awarded £986,176.28 in 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) £1 billion Net Zero Innovation Portfolio (NZIP). 

The project, led by Imperial’s Professor Chris Cheeseman, tackles one of the construction industry’s most acute business challenges: how to make concrete a more sustainable building material.  

Concrete is the world’s second most consumed resource after water, and is widely used for commercial, industrial and domestic construction projects. The binding ingredient in concrete is Portland cement, which accounts for eight per cent of all global CO2 emissions. Developing more sustainable alternatives is a key priority.   

New CO2 capture process 

Imperial researchers are designing a more sustainable building materials that are capable of capturing carbon. Their project transforms magnesium silicate minerals such as olivine, which are naturally abundant, into a supplementary cementitious material while simultaneously capturing CO2 in a form that can be used in a range of sustainable construction products.  

The new process breaks down olivine into its constituent components - magnesia and silica. The silica can then be used as a supplementary cementitious material(SCM) in concrete. Supplementary cementing materials 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 government funding will be used to further develop and optimise the silica SCM and magnesium carbonate construction products, subjecting them to comprehensive testing regimes. 

Professor Cheeseman, of the Department of Civil and Environmental Engineering at Imperial, 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.”

Minister for Energy Security and Net Zero Graham Stuart commenting on all the latest project winners, said: “Whether it's the first meal of the day or a night cap, the great manufacturers of our country are striving to cut their carbon emissions and their energy bills - and in turn, support our efforts to boost our energy security. Our investment of over £80 million will help them to go further and faster, using the latest science, technologies, and new energy sources to cut ties with fossil fuels and futureproof their industries." 

 Lord Callanan, Minister for Energy Efficiency and Green Finance, added: “Britain has a long and proud history of pushing the boundaries in science – and our backing with over £80 million for these cutting-edge projects today will help make way for the next era of innovation. The transition away from fossil fuels presents a huge opportunity for our growing green energy sector and we will continue to make sure UK business can benefits from its full potential.”