Recycled cement best suited to CO2 mineralization

Cement recycling is a cheap and efficient way of achieving lower emissions if the cement is permanently mineralized with emitted and atmospheric CO2. Of the ten technologies examined in a study, the method that uses recycled cement paste made from demolished concrete from infrastructure and buildings proved to be the most effective and economical. It has the potential to reduce emissions from cement manufacturing by around 15 percent. In 2020, this would have corresponded to a total of 0.8 percent of global greenhouse gas emissions.

This is the conclusion reached by a study led by researchers from Imperial College London, in which scientists from the Swiss Federal Laboratories for Materials Science and Technology (Empa) and the Swiss Federal Institute of Technology Lausanne (EPFL) are also involved.

According to a report published by Empa, construction materials are responsible for around 13 percent of global greenhouse gas emissions, most of which come from the production of concrete and steel. “Our findings suggest that CO2 mineralized cement paste could be a champion technology in helping us decarbonize the sector”, comments lead author Rupert J. Myers in the report.

Although a wider application of CO2 mineralization on the basis of end-of-life concrete or other calcium-based industrial waste is limited due to the volume of material to be carbonized, co-author Ellina Bernard from the Concrete and Asphalt Laboratory at Empa states that “CO2 savings of 15 percent in the production of useful building products are not negligible”. Moreover, she goes on to state that attention should now turn to optimizing Carbon Capture and Utilization technologies in addition to cutting costs. ce/mm