NEWS Concrete is the world's most widely used building material – but the production of cement, its key component, generates significant carbon dioxide emissions. New research at Umeå University shows how electrification and carbon capture can make production both more energy-efficient and climate-smart.
Through advanced experiments and analysis of cement clinker composition, José Aguirre Castillo, a doctoral student at Umeå University, has demonstrated how new methods can enable more sustainable cement production.
ImageHeidelberg MaterialsThe cement industry accounts for approximately eight percent of global carbon dioxide emissions. These emissions mainly originate from chemical reactions when limestone is heated and from the fossil fuels used in production. By electrifying the production process and implementing carbon capture, emissions can be reduced. This has been investigated in a doctoral thesis at Umeå University.
José Aguirre Castillo, an industrial doctoral student at Umeå University and process engineer at Heidelberg Materials Cement Sweden, has examined how different carbon capture technologies – such as electrified plasma heating, oxy-fuel combustion, and calcium looping – affect cement production. In these technologies, cement is produced in environments with extremely high carbon dioxide concentrations. José Aguirre Castillo has discovered that this can actually enhance production efficiency, as it facilitates the formation of key minerals in the cement.
“Our results show that high carbon dioxide levels can promote high-temperature reactions. By leveraging this, we have optimised the material with promising results, improving both the product's properties and reducing its climate impact,” says José Aguirre Castillo.
The rotary kiln in the “rock lab” at Tec-lab, Umeå University, is designed for experiments under high carbon dioxide levels. The kiln's silica tubes can be heated up to 1600 degrees Celcius and was set to 1450 degrees for these experiments. The image shows fully sintered cement clinker produced according to an optimised recipe.
ImageJosé Aguirre CastilloThe research shows that a key component of cement, the mineral tricalcium silicate, can be formed more efficiently with carbon capture. Since tricalcium silicate normally requires a lot of energy to produce, production adjustments made to reduce emissions could also lead to a more energy-efficient production process and improved cement quality.
José Aguirre Castillo has also explored how the composition and particle size of raw material can be adjusted to lower energy consumption while making the clinker more reactive. Increased reactivity creates the conditions for diluting the cement with alternative binders, such as volcanic material, further reducing the climate impact.
Umeå University is conducting extensive research on sustainable cement and quicklime production in collaboration with Sweden’s leading industrial players in the field. Several studies have contributed valuable knowledge to support the transition that the cement industry is facing.
José Aguirre Castillo's doctoral thesis shows that carbon capture can be integrated into existing cement plants without compromising cement quality. This enables the industry to reduce emissions while maintaining the strength and durability of the cement.
On Thursday, 20 March, José Aguirre Castillo, Department of Applied Physics and Electronics, will defend his doctoral thesis titled “Cement clinker formation in concentrated carbon dioxide atmospheres. Mineralogical and reactivity insights”. The defense will take place at 13.00 in KBE301 – Lilla hörsalen in the KBC building.
