CO₂ emissions from the cement industry can be reduced without CCS
Cement emissions in the EU fell more than 10 per cent in 2019–2020, demonstrating that fast, short-term cuts are possible.
EU emissions from cement production are of the same magnitude as total CO₂ emissions from an entire country such as the Czech Republic or Belgium.
Those emissions are of two kinds. One is CO₂ from the core process, which drives out CO₂ from the limestone to create cement clinker. Limestone is a fossil-rich rock, often 400 million years old.
The other part is CO₂ from fossil fuels, such as coal, used to heat the limestone.
Emissions from cement-making, as recorded by the EU Emissions Trading System, fell from 116.5 million tonnes of CO₂ in 2019 to 104.6 million tonnes in 2020.
Construction fell by about 5 per cent, largely due to Covid lockdowns in the second quarter of 2020. But that does not explain why emissions fell by more than 10 per cent.
One explanation is the increasing price of CO₂ in the Emissions Trading System. The cement industry has roughly 100 per cent free allocation, but it still has some incentive to cut emissions and sell the surplus, for example by cutting coal use and replacing it with waste fuel or electricity.
The use of ordinary Portland cement may also have decreased slightly, replaced by other cementitious materials. The market for such material is growing, see AN 4/20. Heidelberg Cement states in its Annual Report 2020:
“We have made further progress in the CO₂ of cements with less clinker, thereby achieving a reduction in both CO₂ emissions and costs. In several countries, the proportion of blast furnace slag, fly ash, and limestone in cement has been increased, thus reducing the clinker content.”
If the cement industry does not shrink its carbon footprint of its own accord, it can be forced to do so by external competition from the construction industry.
The decline in cement-making emissions may also to some (small) degree have been replaced by completely different materials, such as wood, rock, or by reducing the cement-to-concrete ratio in some applications. Requirements for the high alkalinity of Portland cement may have been replaced by other reinforcement materials, such as glass fibre or stainless steel.
One thing that has clearly not cut emissions during 2020 is carbon capture and storage. Though widely hyped for a long time, there is still not a single cement plant in the world that uses CCS. In 2024, Heidelberg cement aims to capture 0.4 million tonnes per year in Norway – about 0.04 per cent of emissions in the ETS, of which Norway is part.
The actual reduction in 2020 contrasts with the very modest ambitions by the industry and governments, summed up by the IEA 2020 World Outlook. It does not foresee any change in the core process by 2030, only a modest decrease of CO₂ intensity from 0.54 to 0.48 tonne of CO₂ per tonne of cement between 2018 and 2030 – or one per cent per year.
This is echoed in a recent report from Agora Energiewende, Breakthrough Strategies for Climate-Neutral Industry in Europe.
“Several European cement companies are working on commercialising CO₂ capture technologies and long-term CO₂ storage before 2030. We assume that by 2030 around 10 cement plants that are close to the Atlantic Ocean or to navigable rivers could be connected to long-term CO₂ storage sites that are currently being developed in the Netherlands and Norway. This could reduce emissions by 9 MtCO₂ by 2030.”
The reason why Agora Energiewende accepts such slow progress – a smaller reduction in 11 years than the actual reduction in the year 2020 – is that they accept the industry’s view on investment cycles:
“Given the long technical lifetimes of cement plants – between 50 and 60 years – each reinvestment decision should devise an individual decarbonisation roadmap that is in line with achieving climate neutrality by 2050.”
But Agora Energiewende has high hopes for later CCS:
“In the future, the development of a CO₂ infrastructure could also pave the way for negative emissions via BECCS. By using a large share of sustainable biomass in its fuel mix and sequestering the biogenic carbon share, cement works that are connected to a CO₂ infrastructure can generate negative emissions.”
An alternative view would be that Portland cement has to go the same way as fossil fuels: phased out as soon as possible. Coal use is falling fast. Fossil gas is ever more controversial in the EU.
Can civilization thrive without Portland cement?
Yes. Large buildings and civil structures were built long before Portland cement was invented in the 1840s. If it needs to be done, it can be done.