A new technique to make low-emission cement at scale has been hailed as “an absolute miracle”.
The new method has been devised by researchers from the University of Cambridge, who say it could be crucial in a move to a net zero world.
Making concrete is highly polluting and is responsible for more than 7% of greenhouse gas emissions. The new method uses waste from demolished buildings which researchers say could save billions of tonnes of carbon by 2050.
“We have definitely proved that cement can be recycled into cement,” said Julian Allwood, of the University of Cambridge.
“We are on course for making cement with zero emissions, which is amazing.”
The method uses the electrically-powered arc furnaces used for steel recycling to simultaneously recycle cement, according to reports in Nature and the New Scientist.
Scaling rapidly, the Cambridge Electric Cement process does not add any significant costs to production and significantly reduces emissions.
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Researchers say they could be producing one billion tonnes per year by 2050, which represents roughly a quarter of current annual production.
“Producing zero emissions cement is an absolute miracle, but we’ve also got to reduce the amount we use,” said Allwood.
“Concrete is cheap, strong and can be made almost anywhere, but we just use far too much of it. We could dramatically reduce the amount of concrete we use without any reduction in safety, but there needs to be political will to make that happen.
“As well as being a breakthrough for the construction industry, we hope that Cambridge Electric Cement will also be a flag to help the government recognise that the opportunities for innovation on our journey to zero emissions extend far beyond the energy sector.”
Last year, it was reported that waste clay from HS2 could be used to help create concrete.