Following the late-2009 Concrete Sustainability Hub opening at the MIT Department of Civil & Environmental Engineering, the university’s Technology Review has ranked a magnesium-based cement among 2010 Top 10 Emerging Technologies
Sources: Novacem Ltd., London; Massachusetts Institute of Technology, Cambridge, Mass.
Following the late-2009 Concrete Sustainability Hub opening at the MIT Department of Civil & Environmental Engineering, the university’s Technology Review has ranked a magnesium-based cement among 2010 Top 10 Emerging Technologies. Milled from minerals for which proven reserves exceed 10 trillion tons, Novacem has the potential to absorb more carbon dioxide than is released during production–as much as 100 kilograms of the greenhouse gas per ton. A working formulation of what developers dub carbon-negative cement was devised by Nikolaos Vlasopoulos, chief scientist at London-based Novacem Ltd., an Imperial College London start-up.
Novacem now is refining the product to achieve mechanical performance equal to that of portland cement–a goal that Vlasopoulos asserts is attainable within one year. A pilot batch plant has been built in Novacem’s laboratories to be followed by a semi-commercial facility. Licensing of the first volume-output plants is anticipated in 2014-15, when production and use of the cement will be licensed on a nonexclusive basis worldwide.
Vlasopoulos formulated the recipe as an Imperial College grad student when he was investigating cements produced by mixing magnesium oxides with portland cement: adding water to the magnesium compounds absent portland in the mix, he discovered a solid-setting cement that did not rely on carbon-rich limestone. As it hardened, atmospheric carbon dioxide reacted with the magnesium to make carbonates that strengthened the cement while trapping the gas. Thus, Novacem’s technology is based on magnesium silicates rather than limestone (calcium carbonate) as used in traditional portland cement. The company converts magnesium silicates into magnesium oxide using a low-carbon, low-temperature process and adds special mineral additives to produce Novacem cement.