Decarbonizing the cement industry: A race between economy and ecology

Cement is the second most used material in the world after water. However, the cement industry is also one of the two largest producers of carbon dioxide, accounting for up to 7% of man-made emissions worldwide. Decarbonizing the industry constitutes a significant lever in the fight against global warming but comes with numerous challenges for all market participants simultaneously. Carbon avoidance must be economically viable, new technologies need swift transition to commercial operation, and companies must secure access to competitively priced decarbonized energy. Overall, it resembles a conflicting race between economy and ecology. As a key technology partner, thyssenkrupp Polysius supports its clients on this journey with a high sense of urgency.

Dr. Luc Rudowski has been working for thyssenkrupp Polysius for almost 30 years. He began as a sales engineer and now he oversees the strategic future orientation of the business segment. In his role as Head of Innovation he knows the significant challenges posed by the decarbonization process.

The production of cement generates CO₂ emissions from two primary sources. Approximately 40% stems from the combustion of fossil fuels to heat kilns, while around 60% is released during the thermal decomposition of limestone into carbon dioxide and lime, a crucial component of clinker, which is the principal ingredient in cement, imparting its strength. “Using alternative fuels to get rid of fossil fuels or substituting part of the clinker in cement by Supplementary Cementitious Materials (SCMs) with a lower carbon footprint are the most economical ways to decarbonize cement,” explains the expert. However, the leverage for carbon avoidance is constrained. “The biggest impact on carbon avoidance will be achieved by Carbon Capture Technologies (CCT) that can reduce CO₂ emissions up to 90% but with subsequent high carbon avoidance costs,” states Dr. Rudowski. In fact, it is expected to double the cement production costs due to the huge investments for the implementation of CCT, creating the fitting infrastructure such as pipelines as well as provisions for storage and usage of CO₂.

Furthermore, decarbonization via Carbon Capture Technologies would necessitate a 30 to 50% increase in the energy requirements for cement production. Hence, the solution lies in combining various approaches.

Decarbonizing cement at various levels.

With polysius® pure oxyfuel, thyssenkrupp Polysius has developed one of the most promising Carbon Capture Technologies. The principle is to use pure oxygen instead of air in the fuel firing process of clinker production to eliminate nitrogen from the air and concentrate the CO₂ to more than 90% in the flue gas. With a downstream purification unit, CO₂ can be further concentrated to more than 99,5%, facilitating transportation and storage. In addition to its significant ecological impact, the technology's cost-efficiency also influences customers' decision-making processes. „Our patented polysius® pure oxyfuel process offers the best total cost of ownership compared to other carbon capture technologies,” Dr. Rudowski declares.

Another highly compelling development, representing a true breakthrough, is meca-clay. The concept involves producing activated clay as Supplementary Cementitious Materials (SCMs) to partially replace clinker, utilizing a fully electrified process instead of the traditional thermal method. It is the first time in history that a hydraulic binder can be produced via a non-thermal process, but a mechanical one, using our so-called polysius® charger. The breakthrough technology enables the production of carbon-neutral activated clay when powered by renewable electricity. “We just signed the contract for the implementation of our first demo-scale plant in the Allmendingen plant of Schwenk Zement with a rather large polysius® charger of 3 MW,” Dr. Rudowski reveals.

Regulatory frameworks and political initiatives in decarbonizing the cement industry

While the US federal government is favoring incentives aimed at stimulating the development of projects including decarbonization technologies, the EU used a more regulatory framework with the Emission Trading System (ETS) that essentially sets a price on the CO₂ footprint of cement produced inside EU borders. This mechanism incentivizes investors to encourage and reward cement producers in formulating their decarbonization strategies. “ETS is funding the EU innovation fund, enabling technology companies like ours to innovate and develop new technologies“, reports Dr. Rudowski. However, the ETS has also fostered a green market within the EU, attracting investors from beyond its borders to capitalize on opportunities to invest in green cement production for export to Europe. Driven by these dynamics, the entire industry is undergoing significant transformation, both in Europe and globally.

Decarbonizing cement: Nothing less than an industrial revolution

New challenges, new technologies and ecosystems, as well as new players, are reshaping the entire industry perspective, igniting a battle of technology concepts. The question of which technology will emerge on top hinges on its ability to maximize the reuse of existing industrial assets while reducing industrial risks. “We do realize that our clients will face huge investments in decarbonizing. Re-using existing industrial assets is key to reduce their Capital Expenditures. Accordingly, as part of the market requirements of our innovation strategy to design and incorporate in our green portfolio new build and retrofit solutions,” the expert explains. The competitiveness of companies on the long term will depend on their ability to swiftly develop and deploy the best technologies with the right partners, along with smart business models. That results in a clearly defined task for thyssenkrupp Polysius and the future of the business unit. “To remain successful in the future, we need to get clarity on our future market through green market intelligence and to be ahead in terms of innovation. We want to deliver innovative solutions, with USPs, take our share of the decarbonization market and deliver profitable business.”

More insights into sustainable technologies from thyssenkrupp in our stories.