From problem to product

To see into the future of the cement industry, travel to northern Germany and Holcim’s operation in Lägerdorf. Rich chalk deposits there have been used for more than 160 years to produce the coveted binding agent for concrete around the clock. This amounts to 1.5 million tonnes annually, in the process releasing 1.2 million tonnes of CO2 into the atmosphere. The cement industry is one of the world’s largest greenhouse gas emitters. But this is set to change, at least in Lägerdorf. “We want to be one of the very first cement works to become climate neutral in the next six years,” says Arne Stecher.

Arne Stecher is head of decarbonization at Holcim Germany. In his 25 years there in management roles, he has never seen anything like the current situation. “We are currently in the midst of a global transformation, with fossil value chains disappearing and new green ones emerging. All companies must change,” says Arne Stecher. Not just to save the climate, but also to safeguard their own future. But while many industries can go green by switching fuels or processes, that does not work in cement manufacturing: two-thirds of emissions arise from burning the cement clinker in a kiln. This process decomposes chalk, or calcium carbonate (CaCO3), into calcium oxide (CaO) and CO2. “There will never be cement without carbon dioxide,” says the process engineer.

In 2016 the Paris Agreement on climate change had just come into effect. This led top managers at Holcim, one of the world’s leading building materials groups, to ask themselves two questions: How can we economically capture millions of tonnes of unavoidable CO2? And what will we do with it then? “We scanned the market and the research on carbon capture technologies, identified 80 interesting approaches and initiated 50 pilot projects worldwide,” says Arne Stecher. “This will produce maybe 25 real-life industrial projects, and a handful of technologies will ultimately emerge.”

All three of the company’s German plants are implementing pilot projects. In Lägerdorf, construction will begin in 2024 of a new kiln line using the innovative oxyfuel process, which involves blasting pure oxygen into the combustion chamber where clinker is made, in place of the atmospheric air commonly used to date. The resulting flue gas stream is almost entirely ultrapure carbon dioxide, which is simple to collect and use. “However, there are modifications and new construction involved, as well as investments costing hundreds of millions of euros, so this integrated approach only works at large sites with long-term raw material availability,” says Arne Stecher.

Holcim Germany, says the decarbonization expert, is a first mover in carbon capture and utilization (CCU), both within the group and for the industry as a whole. Arne Stecher is convinced that the pioneering role is worthwhile: When he first started taking interest in CCU, a ton of CO2 cost 20 euros in European emissions trading; in 2022, the price was 80 euros. “The time has already come where it makes sense to invest in avoidance technologies,” he emphasizes. As a first mover, Holcim also occupies an emerging market: the market for CO2. “The new green value chains will not function without CO2; the chemical industry alone will always need a carbon source,” says the head of decarbonization. And that is something Holcim can supply in the immense quantities required. CO2 will go from being a problem to a product. “I believe that CO2 will be a coveted raw material in future,” says Arne Stecher.