Linda Wang
Andrea Valvano
Erna Kalpala
Tuomas Laine
Hanken School of Economics
Martin Fougere
Eva Nilsson
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Soil stabilization is a process in construction where clay-rich soils are stabilized with limestone-based products in order to improve the load-bearing features of the land beneath buildings. This traditionally is done by using soil stabilization products that consist mostly of cement and/or quicklime, both of which in their traditional form cause high CO₂ emissions during the production process. To address this problem, Nordkalk has launched a new Nordkalk Terra GREEN low-carbon soil stabilization product with a new recipe developed to reduce CO₂ emissions, where cement and quicklime have been largely replaced with other natural minerals and manufacturing side stream materials.
The innovation targets the following UN SDGs: Firstly, the innovation contributes to SDG 12, “Responsible consumption and production” as it is driven by the idea of resource consciousness and utilizes side streams and other resources that would not otherwise be used. Secondly, the innovation contributes to SDG 9, “Industry, Innovation and Infrastructure” by providing a more sustainable alternative to the construction industry compared to existing soil stabilization products. Finally, the innovation contributes to SDG 13, “Climate Action” by reducing the CO₂ emissions of soil stabilization products.
Calcium carbonate (CoCO₃) is a natural mineral that is excavated from a quarry and used in the cement and quicklime manufacturing process. When limestone is heated (burnt), CoCO₃ dissolves into CaO (c. 50%) and CO₂ (c. 50%). This means that burning 1000 kg of CoCO₃ leads to about 500 kg of CO₂ emissions no matter what heating energy source is used. This makes the cement industry a huge CO₂ emitter; in fact, if the cement industry were a country, it would be the third largest CO₂ emitter in the world with up to 2.8 billion tonnes, surpassed only by China and the United States.
To reduce emissions from soil stabilization, Nordkalk has launched a new soil stabilization product where the amount of highly emitting cement and quicklime have been replaced nearly entirely with manufacturing sidestream materials, reducing the CO₂ emissions. The recipe of the product has also been changed and developed; previously, soil stabilization production used basically 100 % cement and quicklime, but now Nordkalk has been able to reduce the use of highly emitting raw materials to only around 30-50 % of all raw materials used. This has been done by substituting cement with alternative raw materials (natural minerals), which have a lower carbon footprint. In addition, the company manufacturing cement (Finnsementti) has been able to reduce the CO₂ emissions related to cement by increasingly using manufacturing sidestreams in their production process of cement. The combination of these changes has significantly reduced the CO₂ emissions related to soil stabilization products.
According to the interviewees, Annica Lindfors, Nordkalk’s Business Development Director, and Mathias Snåre, Nordkalk’s R&D Director, the main trigger for this innovation was really the market trend. According to them, there is currently a hard push on sustainability and environmentally friendly solutions in the construction segment, and as the cement and quicklime industries are big carbon dioxide emitters, Nordkalk saw an opportunity in choosing other alternative recipes for the production of soil stabilization products. In short, “the market trend and the end customers are very much signaling for a more sustainable product, which was also a trigger from our perspective.”
Traditionally, cement and quicklime have played an essential role in the construction industry. They are binders, substances used for construction that set, harden, and adhere to other materials to bind them together. World production of cement is about four billion tons per year. In fact, concrete, which is made out of cement, is the most consumed material in the world (di Stefano 2022). Hence, finding less emitting solutions to these highly emitting materials is vital in the transition to a more sustainable future.
Nordkalk’s new innovation helps to significantly reduce CO₂ emissions of soil stabilization, which is an important part of the construction process. This is done by using more manufacturing side-stream materials and replacing highly emitting components with natural minerals. Also, more efficient use of production sides-treams increases the utilization of excavated materials. Finally, as highly emitting limestone-based ingredients have been replaced by other materials, the overall emissions of soil stabilization will significantly decrease.
The significance of Nordkalk’s innovation becomes even clearer when considering the global megatrend of urbanization; due to urbanization, it is predicted that 70% of the global population will live in cities by 2050 (currently the number is around 50 %) (The World Bank 2022). This means that a lot of new construction will be needed to accommodate those people in the growing cities, and with traditional techniques that would result in unsustainable amounts of CO₂ emissions. With help of this innovation, the emissions of soil stabilization part of the construction process could be significantly reduced.
There are several reasons why the innovation benefits Nordkalk’s business. Firstly, it can be seen as a defensive action, as the demand for more sustainable soil stabilization products is growing and the market for the traditional, highly emitting cement and quicklime products will likely not be there in the long run. Coming up with new, more sustainable innovations for soil stabilization is vital to a company like Nordkalk. In the future, it will no longer be feasible to build a business on traditional cement and quicklime production.
Secondly, developing less emitting solutions is feasible because the old product is heavily affected by the emissions trading scheme. In 2022, the price of emission rights has increased considerably compared to last year, and the war in Ukraine has also caused an increase in the price of energy. For those reasons, the price of traditional mixes of lime and cement in particular has risen significantly. Hence, coming up with less CO₂ and energy-intensive products is also feasible from an economic point of view.
Simultaneously, awareness of the emissions caused by traditionally used binders, such as quicklime and cement, has created a growing interest in circular economy solutions. In Nordkalk’s products, lime-based side-streams, for instance, blast furnace slag generated in the steel industry or lime kiln dust (LKD), have been used for a long time, but recently the demand for such products has risen to a whole new level. Being able to answer this demand is beneficial to the company.
The innovation is significant when it comes to the environment. Considering the amount of emissions created by traditional cement and quicklime production, and the growing need for soil stabilization products in the quickly urbanizing and developing world, it is very important to be able to reduce the emissions generated by the construction industry. The fact that the new soil stabilization product can make the carbon footprint significantly smaller is a grand achievement. This is especially evident when thinking about the fact that in 2016 cement production generated 8% of the global total CO₂ emissions. Nordkalk’s innovation has the potential to significantly contribute to the cutting of global emissions.
Of course, cutting emissions will also benefit societies as the health risks of air pollution will decrease, and fewer emissions also contribute to less global warming. The circular model used by Nordkalk means that not as many virgin materials will need to be excavated, which will also help save resources.
References:
Di Stefano, D. (2022). Cement: The Most Destructive Material in the World or a Driver of Progress? Renewable Matter No. 38 / Circular Building. Available from: https://www.renewablematter.eu/articles/article/cement-the-most-destructive-material-in-the-world-or-a-driver-of-progress. Accessed 16.10.2022.
The World Bank (2022). Urban Development. Available from: https://www.worldbank.org/en/topic/urbandevelopment/overview#:~:text=Today%2C%20some%2056%25%20of%20the,people%20will%20live%20in%20cities. Accessed 10.10.2022.
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Annica Lindfors, Business Development Director
Mathias Snåre, Nordkalk’s R&D Director
Nordkalk is the leading limestone company in Northern Europe with operations in more than 30 locations in Europe. The company contributes to a brighter future with help of limestone, a natural stone that nurtures the ground that feeds us, purifies the water we drink and the air we breathe, and is essential for several critical industrial processes, such as steel, pulp and paper. The company employs around 820 people and has its headquarters in Pargas, Finland.