British engineers have developed a new environmentally friendly cement that is carbon-negative.
Cement, a vast source of planet-warming carbon dioxide, could be transformed into a means of stripping the greenhouse gas from the atmosphere, thanks to an innovation from British engineers.
The new environmentally friendly formulation means the cement industry could change from being a “significant emitter to a significant absorber of CO2,” says Nikolaos Vlasopoulos, chief scientist at London-based Novacem, whose invention has garnered support and funding from industry and environmentalists.
The new cement, which uses a different raw material, certainly has a vast potential market. Making the 2bn tonnes of cement used globally every year pumps out 5% of the world’s CO2 emissions – more than the entire aviation industry. And the long-term trends are upwards: a recent report by the French bank Credit Agricole estimated that, by 2020, demand for cement will increase by 50% compared to today.
Making traditional cement results in greenhouse gas emissions from two sources: it requires intense heat, and so a lot of energy to heat up the ovens that cook the raw material, such as limestone. That then releases further CO2 as it burns. But, until now, noone has found a large-scale way to tackle this fundamental problem.
Novacem’s cement, based on magnesium silicates, not only requires much less heating, it also absorbs large amounts of CO2 as it hardens, making it carbon negative. Set up by Vlasopoulos and his colleagues at Imperial College London, Novacem has already attracted the attention of major construction companies such as Rio Tinto Minerals, WSP Group and Laing O’Rourke, and investors including the Carbon Trust.
The company has just started a £1.5m project funded by the government-backed Technology Strategy Board to build a pilot plant. If all goes well, Vlasopoulos expects to have Novacem products on the market within five years.
Jonathan Essex, a civil engineer at the building consultancy Bioregional who also sits on the environment and sustainability panel for the Institution of Civil Engineers, welcomed Novacem’s ideas to tackle the carbon impact of cement. “In the UK the climate bill commits us to reduce CO2 emissions, and every sector should play its part. The construction industry needs to take greater responsibility for its own environmental impact.” Essex said that, if Novacem can make their cement at a competitive price, the next step could be to take even more CO2 emissions out of the process by using renewable energy to fire the furnaces.
According to Novacem, its product can absorb, over its lifecycle, around 0.6 tonnes of CO2 per tonne of cement. This compares to carbon emissions of about 0.4 tonnes per of standard cement. “From that point of view, it’s attractive,” said Rachael Nutter, head of business incubators at the Carbon Trust. “The real challenge is what is the supply chain, who do you need to partner with to take it to market? The million-dollar question is what are the applications of it? If it ends up as decorative applications such as floor tiles, it’s quite interesting but not as much as if you get into load-bearing structural stuff.”
Previous attempts to make cement greener have included adding more aggregate to a concrete mixture, thereby using less cement. But this still does not tackle the problem of the carbon emissions from making the cement in the first place. Other systems use polymers in the mix, but none have yet made a significant impact on the market.
A spokesperson for the British Cement Association expressed a sceptical note, saying that though there was much ongoing laboratory work on new types of cement, there were also problems. “The reality is that the geological availability, and global distribution, of suitable natural resources, coupled with the extensive validation needed to confirm fitness-for-purpose, make it highly unlikely that these cements will a be realistic alternative for volume building.”
Vlasopoulos responded that magnesium silicates are abundant worldwide, with 10,000 billion tonnes available, according to some estimates. “In addition, the production process of our cement is of a chemical nature, which means it can also utilise various industrial byproducts containing magnesium in its composition.” He is confident the material will be strong enough for use in buildings but acknowledged that getting licenses to use it will take several years of testing.
Explainer: Ecofriendly vs traditional cement
Standard cement, also known as Portland cement, is made by heating limestone or clay to around 1,500C. The processing of the ingredients releases 0.8 tonnes of CO2 per tonne of cement. When it is eventually mixed with water for use in a building, each tonne of cement can absorb up to 0.4 tonnes of CO2, but that still leaves an overall carbon footprint per tonne of 0.4 tonnes.
Novacem’s cement, which has a patent pending on it, uses magnesium silicates which emit no CO2 when hearted. Its production process also runs at much lower temperatures – around 650C. This leads to total CO2 emissions of up to 0.5 tonnes of CO2 per tonne of cement produced. But the Novacem cement formula absorb far more CO2 as it hardens – about 1.1 tonnes. So the overall carbon footprint is negative – ie the cement removes 0.6 tonnes of CO2 per tonne used.
*This article was written by Alok Jha and shared with EcoWorldly by The Guardian as part of the Guardian Environment Network
Image credit: pfala via Flickr, under a Creative Commons license.
This carbon-negative cement paired with EcoRock (a drywall that congeals without heat, uses recycled materials that don’t require mining, and holds up even better) from Serious Materials (seriousmaterials.com) could be the ideal solution for a greener building material!
Roshan
Way to go! The technologies to reduce C02 emissions are here, the public will to enforce their use may not be strong enough! Reinforcing public will to use these technologies is equally important and necessary, and may prove to be the most difficult!
First of all there is no correlation of CO2 and warming. It just doesn’t exist. I’m glad someone invented a new type of concrete but if you want to get rid of CO2 go plant a tree. Furthermore, we are probably heading towards a cooling period and yes, CO2 levels will continue to grow.
This is a decent post, but it makes no mention of the other carbon sequestering cement plans out there, nor any useful comparisons. I suggest the following article for those truly interested: http://www.sciam.com/article.cfm?id=cement-from-carbon-dioxide
It seems we need oversight on which technology works the best, and then for a govt or other consortium to come in and buy the rights so the inventor is compensated, but then let the tech be used freely so we can soak up the carbon! We cannot rely on rational market hypotheses when the clock is ticking to zero.
Wow! The British invented something! Perhaps I should keep that little green MG in grandpa’s garage after all?
Whenever there’s mention of pollution of any kind on the TV or on the Web, there’s inevitably a picture of STEAM coming out of factory chimneys and car tailpipes.
Yes, it’s ugly and it makes you feel bad. That’s what’s really important. Carry on.
well, all fine and good….but plants remove more CO2….one field of grass or cornfield would remove the same amount…so, good thinking, in the raw materials are available…
but its not the even in the ballpark as far as a solution to greenhouse gasses are concerned….and a mere distractor, if defforrestation continuues.
Solve the problem? nope…but another good jump on the band wagon…
sorry thing is that the people who run the website, and journalist, would publish this without a critical eye, or evaluation…..but then the public opinion of journalists is falling anyway….
this is ‘eco-propoganda’ not ‘eco-protection’….
Check it out folks: Carbon Dioxide is NOT a pollutant and global warming is a hoax. Doesn’t science matter anymore? You don’t have to believe me, check out http://www.climateaudit.org, unless you are afraid that your sacred cows might be in jeopardy.
RUBBISH. This “invention” was debunked by New Scientist a couple of years ago.
Here man thinks they can take CO2 out of the atmosphere without consequence. What happens if man can really do this? It will create an even bigger imbalance that will throw off growing cycles and even eradicate plant life we now depend on.
I can’t wait for a world crisis to come out of this ‘world crisis’ when man finally says, ‘Oops, we’re screwed!’
ALL SMOKE, AND ALL NON-SOLIDS THAT RISE UP INTO THE ATMOSPHERE SEPARATE WITHIN 20 MINUTE. NATURES WAY OF KEEPING THE ATMOSPHERE CLEAN FOR SUN LIGHT TO MAKE PLANTS GROW. MOST CARBONS MAKE PLANTS FLOURISH MORE AND PLANTS HELP ALL THE LIVING TO BREATHE. LIKE THE FOREST FIRES, IF THE SMOKE WENT UP TO THE OZONE, THE HELICOPTERS WOULD’NT BE ABLE TO SEE TO GO TO PUT THE FIRE OUT. IF FOR THE LAST 45 YEARS THE SMOKE AND WHATEVER WENT TO THE OZONE WE WOULD’NT BE HERE, BECAUSE LIGHT WOULD HAVE BEEN BLOCKED OUT. MIKE
So what happens when it absorbs more than its capacity of Carbon Dioxide? I wonder if these so called scientists take into the consequences…of course they don’t…no-one does anymore. Gonna be a long couple of years :/
It’s a load of cr*p. Debunked.
I think this is a great idea, anything that reduces co2 is a good thing. Like most things it will come down to money though, the only way this will work is if the planning authorities impose it on developers as a condition of getting permission to build.
I agree that it is a great idea, if used properly, but on the other hand if we cling on to one solution for too long and do not try to use others, it will only create a larger problem. For instance: most people do not want to change back to living without technology, but we cannot live without nature. We need to find a balance.
nice comment abaout pollution
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Unbelievable! Kudoz on the invention. But as to the other diatriabe; I can’t believe the majority of people believing in CO2 reduction. It’s the other junk in the atmosphere that isn’t good for the planet. However; the planet has things in place for that. Including Trees and Plants of all kinds for the CO2. If we continue the to strip what plants breathe, eventually they’ll die but first they will lessen. Then we’ll have a lack of oxygen. Then animals and such that depend on oxygen will begin to weaken and die off. Where does the maddening anti-science stop?!
So if 1 tonne of cement absorbs 1.1 tonnes of CO2 over its lifetime, doesn’t that mean it will get over twice as heavy during its lifetime.
If so wont this cause problems structurally?
Yes, cement plants emit CO2 and it is not possible to remove it totally. We need cement to build houses, roads, bridges etc. What we need is an optimisation of the cement use.
On the cement plants we can try to have as little pollution as possible (also other species more dangerous than CO2).
In general if you have raw materials close to the plant with the properties for making this “CO2 friendly” cement (which I don’t really believe in) then you can do it. But how many plants in the world have this opportunity? 5 or less? Just don’t go into moving the raw materials far away for processing – this will only give higher CO2 emissions from the transport of the materials. It is important that this transport is as little as possible.
nice to hear about this product, would i know about the method of preparation about magnesium silicate cement.