The Swiss university École polytechnique fédérale de Lausanne (EPFL) developed the revolutionary cement composition “LC3“ which has the potential to lower global CO2-emissions by 1-2%. The environmental benefits come together with improvements in durability and strength characteristics compared to conventional Portland cement. Very importantly, the innovation is also up to 25% cheaper in production because of energy cost reductions and waste material utilization.The Swiss university École polytechnique fédérale de Lausanne (EPFL) developed the revolutionary cement composition “LC3“ which has the potential to lower global CO2-emissions by 1-2%. The environmental benefits come together with improvements in durability and strength characteristics compared to conventional Portland cement. Very importantly, the innovation is also up to 25% cheaper in production because of energy cost reductions and waste material utilization.
WHY ARE SUSTAINABLE SOLUTIONS IN CEMENT TECHNOLOGY VERY IMPORTANT FOR DEVELOPMENT AND CLIMATE PROTECTION EFFORTS?
With 4’199 million tons of consumption per year, cement is the most produced material in the world and second most consumed item after water. Thereby, the majority of demand comes from fast-growing economies which have high growth rates and strongly invest in construction projects such as China and India. The demand is expected to further increase up to 5’000 million tons per year in 2050. Considering the availability of resources on earth and the magnitude of worldwide demand for building materials, there is no feasible alternative compared to cement. Moreover, it is also a relatively climate-friendly construction material compared to other materials. However, the global cement industry is still one of the largest producers of carbon dioxide (CO2) due the large production figures. In total, it accounts for 5% to 10% of worldwide man-made emissions.
Hence, viable solutions for sustainable development efforts need to focus on reducing the emissions of cement utilisation itself.
POTENTIAL OF LC3 – LOW CARBON CEMENT
In cement, the production of clinker is energy- and CO2-intensive. Firstly, clinker needs to be burnt at very high temperatures between 1400 and 1500°C. Secondly, CO2 embodied in limestone is released during production.
Under the guidance of EPFL in Switzerland, an international joint research team has developed and
tested an innovative cement, which is called Limestone Calcined Clay Cement, or LC3 for short. This new cement reduces the clinker content to 50% and replaces it with widely available and often waste or second grade materials. These are limestone and clay which can be calcined to activate (see illustration).
Clays are produced at a lower temperature and do not release embodied CO2. Limestone is used as is without burning. In result, CO2-emissions of the new Limestone Calcined Clay Cement are 30% lower compared to conventional Portland Cement.
LC3 IS A TECHNICALLY FEASIBLE AND FINANCIALLY ATTRACTIVE SOLUTION
LC3 shows very similar performance characteristics compared to conventional Portland Cement and even outperforms traditional cement in some regards such as resistance to chloride and alkali–silica reaction (called ASR or “concrete cancer”). Apart from the laboratory testing, multiple applications have been constructed and they showed extremely positive results.
Finally, LC3 is also up to 25% cheaper in production due to the reduction of the energy-intensive clinker content with widely available and less energy-intensive materials. Investment costs are also low since already existing technologies can be used for the production of LC3. Moreover, this existing economic attractiveness can be further increased by governments through incentives such as tax-reductions in order to accelerate the production of LC3.
USING LC3 TO ACHIEVE NATIONALLY DETERMINED CONTRIBUTIONS (PARIS AGREEMENT)
LC3 can make a difference to achieve the Intended Nationally Determined Contributions (INDCs) for any country. For example, Colombia expressed its commitment to reduce its CO2-emissions by 20% until 2030 which equals 67 million tons until 2030. A share of approximately 9,3 million tons needs to be achieved in the industrial field.
By introducing LC3 production, Colombia could easily achieve a large proportion of its climate protection commitment. Even in a conservative scenario of 50% LC3-use in the industry by 2030, the LC3 could already make a third of the expected savings within the industry sector and 5% for the overall NDC-commitment. With 100% LC3-use this impact could be doubled.
On a global level, it is estimated that the utilization of LC3 can save up to 400 million tons of CO2 per year by 2050. This amount equals France’s entire yearly carbon dioxide emissions or the 1-2% of global CO2-emissions.
When looking at LC3 in terms of frameworks such as the Sustainable Development Goals (SDGs), the potential to contribute to climate action efforts becomes clear. LC3 can be directly associated with 5 of the 17 Sustainable Development Goals, as shown below:
Climate protection and development efforts often conflict but LC3 means that we do not have to choose between these objectives anymore. In fact, LC3 is the answer to both of these important goals together. Similar constructions projects can now be realised with a more efficient material which thereby saves 30% of CO2-emissions. Hence, LC3 is a solution well-adapted for sustainable development ambitions.