Cement is a wonderfully useful building material, and its durability and long lifespan help earn it some green-building credibility – but only up to a point. Traditional cement production carries a massive carbon footprint – up to 5% of worldwide industrial emissions by some estimates. The solution? The best of both worlds may be Novacem, a carbon-negative formulation that aims to match the performance and cost of traditional Portland cement – minus the pollution.
The carbon output of the cement industry is so huge because the industry itself is enormous: 2.9 billion tons of cement are produced annually, and that figure grows each year. A single ton of normal Portland cement produces a whopping 800kg of CO2, roughly half of which comes from the calcium carbonate raw materials, and half from fueling the manufacturing process.
Developed in the UK, Novacem is fundamentally different in that it uses magnesium oxide (MgO) and hydrated magnesium carbonates, which are widely available and accessible around the world. These materials not only require far less fuel to produce the end product, but the carbonates actually absorb CO2 during manufacturing.
According to Novacem:
“The low temperatures required allow use of fuels with low energy content or carbon intensity (i.e. biomass), thus further reducing carbon emissions. Additionally, production of the carbonates absorbs CO2; they are produced by carbonating part of the manufactured MgO using atmospheric/industrial CO2. Overall, the production process to make 1 tonne of Novacem cement absorbs up to 100 kg more CO2 than it emits, making it a carbon negative product.”
(images courtesy of Novacem)