A team of researchers led by the University of Colorado Boulder, USA, has received a US$3.2m grant from the US Department of Energy to support the development of algae-grown cement.

The university’s Will Srubar, associate professor in civil, environmental and architectural engineering, developed a way to harvest cement material from calcifying algae that consume water-dissolved CO2 to produce limestone by photosynthesis.

Algae-grown cement is carbon neutral because the same amount of CO2 needed to make it ready for use in concrete is captured by the algae as they make the limestone, according to his calculations. It is claimed it could even be carbon-negative if ground limestone filler - often used to replace about 15 per cent of kiln-heated cement, is replaced with ground algae-grown limestone.

Professor Srubar believes the switch to so-called “biogenic cement” could theoretically happen overnight because the material is “plug-and-play”, meaning it works with conventional cement-making processes. The research team estimates that 1m-2m acres of open ponds (0.5 per cent of all land area in the country) would produce sufficient cement to meet the entire US requirement for cement.

Commercialisation is underway as last year Prof Srubar co-founded a university start-up, Minus Materials Inc, of which he is acting CEO. It is currently looking for investors and forming corporate partnerships.

The Algal Resources Collection at the University of North Carolina Wilmington, USA, and the National Renewable Energy Laboratory, USA, are also participating in the grant-funded research.