Mineralising CO2 can reduce cement production emissions by a third - study

Cement production is responsible for about seven percent of global greenhouse gas emissions, but a process known as CO2 mineralisation can cut the output of the greenhouse gas by up to a third at no additional cost, according to a study by the Institute for Advanced Sustainability Studies (IASS) in Potsdam and Edinburgh's Heriot-Watt University. “In CO2 mineralisation, the captured CO2 reacts with minerals (e.g., magnesium-rich or calcium-rich silicates) and can be stored permanently – and the resulting product could even bring in additional revenue,” IASS states, adding the mineralisation processes can produce cement additives that can be added to ordinary cement. By integrating CO2 mineralisation into the cement production process, CO2 emissions can be reduced by 8 to 33 percent and generate additional profit of up to 32 euros per tonne, provided certain conditions are met, the study published in Nature found. “The products need to be used as cement substitutes in cement mixtures in construction, for example, in bridges or buildings, and cement standards may need to be adjusted,” said researcher Till Strunge. “Moreover, CO2 storage in minerals must be eligible for ETS [Emissions Trading System] credits or similar.”

The global market size of cement is estimated to reach 463 billion US Dollars by 2026 – some six gigatonnes of cement per year, according to the study. Some 60 percent of emissions from the cement industry are process-inherent, resulting from the calcination of limestone, in which high temperatures are used to remove carbon dioxide from the material, the researchers explain. Carbon capture and storage technologies are an alternative, but incur additional production costs.

In 2020, German cement industry association VDZ presented plans to decarbonise cement and concrete as part of its efforts to become climate-neutral by 2050.