Carbon-negative cement | New revolutionary Building material
Carbon-negative cement…?? Sound different, doesn’t it?
Have you ever realized how much carbon is emitted because of using concrete in the construction of buildings, highways, dams, bridges etc?
Well, here’s an answer to that. It is found that out of the 100% carbon dioxide emissions, 5% of the emissions are caused by human activities. Majority of the carbon emission is caused by usage of concrete in the constructions. How? Cement is an indispensible ingredient used for making concrete. Cement is made by baking limestone and clay powders under intense temperatures (high temperature). The intense heat which is required for the production of cement is achieved by burning of fossil fuels which in turn release large amount of carbon dioxide into the atmosphere.
Carbon dioxide is also released when the conversion of limestone takes place in the kilns. This conversion is called “Calcination”. It has been observed that the amount of carbon dioxide emitted during calcination is much higher than that which is released due to burning of fossil fuels.
Recently, a British company called “Novacem” came up with this concept of manufacturing ‘carbon-negative’ cement that absorbs more carbon-dioxide than it emits over its entire life cycle.
How have they been able to achieve this?
In the production of Portland cement, calcium carbonate or limestone is used as the primary ingredient. So instead of using calcium carbonate or limestone which is responsible for the emission of carbon dioxide into the atmosphere; they are using magnesium silicates since this material does not emit carbon dioxide in the manufacturing process. They are employing low-temperature production processes where the fossil fuels would be replaced by biomass.
It has been observed that this cement absorbs greenhouse gases as its age advances.
Construction industry is aware of the increase in the carbon footprint and also realizes the need to curb it. This will only be possible if we are able to accept these products and try to break away from our conventional materials and working methods.
It has been estimated that for every ton of Portland cement replaced by the new product “carbon negative cement”, three quarters of a ton of carbon dioxide is prevented from entering into the atmosphere.
International cement makers have been striving hard to turn the cement industry from a big emitter of carbon to a big absorber of carbon. They have taken an initiative by investing in modern kilns and using little carbon-heavy fuel as possible but the reductions in carbon release have been limited till date.
We shall discuss more about Green Building Materials in our succeeding articles.