(London, U.K.) — Concrete is indispensible. Millions of tonnes are poured each year in Britain to make everything from motorways to house foundations. But it is also an environmental villain, accounting for 5% of man-made carbon dioxide, more than the world airline industry.
A tiny start-up called Novacem wants to change all that. It claims to have come up with a formula to make concrete that actually absorbs carbon dioxide.
The cement Novacem has developed in its lab in the basement of Imperial College’s Bessemer Building has a different chemical structure to that of traditional cement, which is the basis for concrete, mortar and other building materials. Novacem uses magnesium oxide, which together with other mineral additives, hardens by rapidly absorbing carbon dioxide from the atmosphere.
Novacem’s chief scientist, 29-year-old Nikolaos Vlasopoulos, developed the formula during years of research at Imperial College. It also takes less energy to produce than traditional cement, which must be heated in kilns at temperatures up to 1,600C. Novacem’s cement needs to be heated to only about half that temperature, said Vlasopoulos.
“The carbon footprint of Novacem production is between a third and a half of that of typical Portland cement. Producing a tonne of Novacem creates about 200kg-400kg of carbon dioxide per tonne, compared with about 700kg for Portland cement.”
The setting process gives the largest environmental benefit, he said. “Portland cement can absorb some carbon dioxide during setting, between 100kg and 500kg per tonne, but Novacem can absorb 2.5 times as much.
Novacem’s concrete formula has other advantages, said the firm’s executive chairman Stuart Evans, a veteran engineering and IT entrepreneur brought in by Imperial Innovations, the university’s business incubator, to help commercialise the technology.
“It will be possible to recycle Novacem after a building is torn down, which makes it more sustainable. We will also be able to mix it with waste material such as aggregate, glass or plastic, which you would never do with Portland cement.”
The company is striving to make a product that is as as easy to work with as concrete, said Evans. “The cost of production has the potential to be about the same as for traditional cement and on site Novacem will use the same processes as Portland cement so construction firms will not need to change the way they work.”
Novacem is still far from proving itself commercially, however, let alone taking large amounts of carbon dioxide out of the atmosphere. It has created a test plant in its lab and plans to build a small industrial plant in Britain next year.
Imperial Innovations is providing half of the first £1m it needs. It will need to raise a further £3m next year to continue development. “These are challenging times in which to raise money but we are making good progress on that,” said Evans.
The company is also working with large industry partners including Laing O’Rourke, WSP Group and Rio Tinto, to help set up the first factory and evaluate the technology, said Evans. “We are a new kid on the block in what is a very conservative industry so we need partners to develop this commercially.”
There also plans to license the technology so that it will be taken up quicker, said Evans. “I am hoping there will be several plants producing Novacem within five years. We also have to think about how to sell the technology globally, especially in China, which produces 49% of the world’s cement.”
Novacem’s carbon-absorbing qualities may also enable it to take a cut of any savings its clients make through carbon credits, said Evans. Novacem could take a share in the profits firms make from cutting carbon-dioxide emissions, slotting the clause into its contracts. “If we captured 10% of the global market that would be 300m tonnes of concrete. If the cost of producing carbon dioxide is €30, then that’s €10 billion worth, which we would want a share of.”
The only other carbon-reduction options for the concrete and construction industries would be expensive and unproven carbon capture technology. “For tens of millions of pounds Novacem could offer an alternative to the billions that will need to be spent on carbon capture,” said Evans.
By contrast, creating “carbon negative” buildings could make a huge difference to the industry’s environmental record, said Evans. “The cement industry is a mature one and it does little in the way of fundamental research but there is a chance for it to make a great breakthrough here. If everyone used Novacem, instead of producing 5% of the world’s carbon dioxide they could absorb the same amount.”
By: Nikolaos Vlasopoulos and Stuart Evans