Researchers in Germany aim to reduce cement’s CO2 footprint with recycling procedure

Using residues from industry production in the making of cement can substantially reduce the basic material’s carbon footprint, a group of researchers from the University of Halle-Wittenberg in eastern German state Saxony-Anhalt have found. Limestone-based cement production is one of the biggest and fastest-growing sources of greenhouse gas emissions in the world, but limestone can be replaced with leftover material from the production of kaolin or aluminium, which greatly reduces the procedure’s CO2 intensity without compromising the resulting material’s properties. "I don't really like the term industrial waste. It is actually industrial residues that can still be used very effectively,” said researcher Herbert Pöllmann. However, as the volume of industrial residues cannot cover global demand for cement, the researchers are exploring further alternatives, such as volcanic ashes, suitable for reducing the climate impact of the construction industry.

Reducing the climate impact of several industrial processes is seen as one of the greatest challenges in emissions reduction and still requires intensive research to find low-carbon solutions, which the German environment ministry has set out to support financially. However, companies lament that new technologies are not being deployed because the existing regulatory framework does not offer viable business models. Chancellor Angel Merkel and environment minister Svenja Schulze have said that carbon capture and storage (CCS) technology could be used as a way to offset emissions in areas where a comprehensive reduction is hard to achieve, such as industrial production or agriculture. The debate on CCS has long been considered finished in Germany due to widespread opposition against the procedure in which carbon dioxide is compressed in underground storages.