Governments are implementing stricter environmental regulations, compelling the industry to adopt cleaner technologies and reduce emissions.
Cement is made through a process that turns natural materials into a strong, binding substance used for construction.
The use of Supplementary Cementitious Materials (SCMs) like fly ash, slag, and calcined clay has gained traction as they reduce clinker content, lowering carbon emissions by up to 70-80% in some cases.
Cement made it possible for humans to settle in one place and to urbanize their settlements. The ability to construct public buildings and amenities that could withstand the elements, disasters and even invasion truly laid the foundation for modern society.
Cement production methods are well established, energy intensive, and widespread. The sector is termed hard to abate due to the high tempearture requirements and process related carbon emission.
Cement production starts with quarrying raw materials like limestone, clay, and sand. Alternative raw materials like fly ash, blast furnace slag, and other industrial byproducts, reducing resource use and supporting a circular economy.
The raw materials are crushed into baseball-sized pieces. The crushed rock is ground into fine particles and mixed with materials like clay, chalk, and iron ore.
The fine mixture enters a rotating kiln, where a powerful flame heats it to about 1500 °C. The heat transforms the material into partially molten "clinker."
Inside the kiln, chemical reactions produce a new substance called clinker, which emerges as marble-sized grey balls. The main reaction taking place inside the kiln is the decomposition (calcination) of limestone (CaCO3) to lime (CaO) releasing carbon dioxide gas (CO2)
The clinker is cooled and stored and ground into a fine powder. During this step, gypsum (a mineral) is added to control how quickly the cement hardens.
The cement is now ready for use.
Environmental Impact
Cement production is responsible for approximately 8% of global CO₂ emissions, primarily due to the calcination process the high energy requirements of kilns.
Cement manufacturing is energy-intensive, relying heavily on fossil fuels for high-temperature kilns. Additionally, cement requires substantial amounts of raw materials, leading to resource depletion.
Governments are implementing stricter environmental regulations, compelling the industry to adopt cleaner technologies and reduce emissions.
Many cement plants rely on outdated technology, making it difficult to implement modern, energy-efficient processes. Moreover, integrating new technologies, such as carbon capture and utilization, requires substantial investment and poses implementation challenges.
The cement industry is vulnerable to supply chain disruptions, such as fluctuations in fuel prices, transportation bottlenecks, and geopolitical tensions.
There is increasing pressure from stakeholders and consumers for the industry to adopt sustainable practices and reduce its environmental footprint.
The use of Supplementary Cementitious Materials (SCMs) like fly ash, slag, and calcined clay has gained traction as they reduce clinker content, lowering carbon emissions by up to 70-80% in some cases. Innovations include the development of zero or negative carbon footprint SCMs to produce Near-Zero Emission Cement; such as those derived from steelmaking waste, or use fossil-free energy for cement production.