New research on CCS and electrification examines clinker formation changes

The cement industry is transitioning to more sustainable cement production. New research from Heidelberg Materials provides important knowledge about how cement production will function when adapted with electrification and carbon capture.

José Aguirre Castillo, process engineer at Heidelberg Materials Cement Sweden and industrial doctoral student at Umeå University, has investigated this in his doctoral thesis. Through advanced experiments and analyses of the mineralogy of cement clinker, he has shown how new technology can change processes, creating more sustainable cement production.

Aguirre Castillo's research focusses on how various CCS technologies, such as electrified plasma heating, oxyfuel combustion and calcium looping, affect clinker formation in cement production. These technologies involve producing cement in environments with extremely high CO₂ levels – "Something that radically changes how minerals react at high temperatures," claims Heidelberg Materials.

Using advanced high-temperature X-rays, the research has shown that limestone transforms differently under these conditions, which affects how the key minerals in cement develop. Among other things, the study has shown that high CO₂ levels favour the formation of C₃S, an otherwise energy-intensive mineral that is crucial for the early strength of cement. This is expected to lead to more energy-efficient production processes and improved cement quality.

One of the most interesting results of Aguirre Castillo's research is the insights into how raw materials can be optimised to suit the new production conditions. By adjusting the composition and particle size, the combustibility of the cement can be improved, which reduces energy consumption and creates a more reactive clinker. This increased reactivity of the clinker creates the conditions for diluting the cement with alternative binders, such as natural pozzolans.

“Our results show that high CO₂ levels can benefit reactions at high temperatures. By exploiting this, we have optimised the material with good results, which both improves the product's properties and reduces its climate impact,” says José Aguirre Castillo.

The study also shows how an innovative process for CO₂ capture can be integrated into existing cement production, and how it can be optimised while maintaining the quality of the clinker product.

The research paves the way for more sustainable cement production and has the potential to contribute to one of the major industrial transitions.