Cement industry must be regulated to eliminate its carbon emissions, says environmental expert
Governments must urgently step in to regulate the cement industry in an effort to eliminate its carbon emissions, according to a senior environmental expert.
Myles Allen, an Oxford professor who has served on the UN’s Intergovernmental Panel on Climate Change (IPCC), said that unless the cement trade was incentivised to reduce its emissions, efforts to reach net zero could be stymied.
The production of cement – the active ingredient in concrete – accounts for around 7% of global carbon emissions, a larger proportion than aviation and deforestation combined.
While those emissions are primarily located in emerging and fast urbanising economies such as China and India, and while European cement producers have made great strides in reducing their emissions, eliminating them entirely remains exceedingly challenging, because of the nature of the reaction.
Cement is produced when limestone is heated to high temperatures in a kiln, and that process involves two streams of carbon dioxide emissions: first from the fuel used to heat the kiln (traditionally coal) and second from the chemical reaction itself.
While major producers have reduced their use of fossil fuels for energy and refined the chemical process, eliminating emissions altogether remains an elusive goal.
Andy Spencer, VP Corporate Affairs, Sustainability & ERM for CEMEX, which runs the biggest cement kiln in the UK near Rugby, said: “We are changing the formulation of concrete, and then to a much lower carbon recipe using lots of alternative materials and then the final piece that we cannot yet offset from here, we are using a certified carbon offset scheme.
“We will save around half a million tonnes of CO2 emissions from [this plant] every year.”
However, the cement industry is reliant on a new technology – carbon capture and storage – to eliminate the emissions from the chemical process itself.
Some warn that this technology is unlikely to happen at scale in the foreseeable future.
But Prof Allen said the main way to make that happen would be for the government to impose rules or requirements on the industry to ensure it has an incentive to go green.
He said: “Cement is a commodity industry. The margins aren’t big, so you can’t expect companies to do this out of the goodness of their hearts… So it’s got to be regulated and it’s got to be fair. Ideally, or we should set a timetable for decarbonizing cement across the whole of Europe.”
However, some academics are working on new recipes and new forms of cement which could eliminate carbon emissions altogether.
Researchers at the University of Sheffield are using alkali formulas and waste products from the steel industry to create a form of cement that doesn’t directly emit carbon in its production.
These new cements are similarly resilient to most Portland cement (the traditional variety) and in some senses are even more resilient.
However, Brant Walkley of Sheffield’s Department of Chemical and Biological Engineering, said that it would be tricky to scale them up to replace Portland cement altogether.
He said: “One of the biggest challenges that we have with these materials, with any replacement for Portland cement is to be able to produce it on a scale that can meet the demand for cement and concrete.
“At the moment the world produces 10 billion tonnes of concrete every year – enough to cover a landmass the size of England, every year – so it’s a huge amount.
“Cement is the main ingredient in concrete, it’s the glue that binds everything together. And so to be able to produce an alternative material at the same scale is very, very challenging.”