Energy use is responsible for a third of emissions from the cement production process and real progress has been made reducing these emissions by using alternative fuel sources, enhancing kiln efficiency and electrification.
However, the reduction of process emissions, responsible for two thirds of the emissions associated with the production of cement continues to lag behind. These process emissions are the unavoidable consequence of the chemical reaction that occurs when limestone decarbonises to produce clinker, the main ingredient in cement.
In recent years, Carbon Capture Utilization and Storage (CCUS) has emerged as the focus for large scale process emissions decarbonisation. And while CCUS will be essential in any long-term decarbonisation plan for the cement industry, it faces multiple challenges. It is hugely expensive, it will only be suitable for a small number of cement plants, is commercially unproven and unlikely to be available for wide roll-out until the late 2030s.
Meanwhile, the UN Environmental Programme report, High-Filler Cements: Potential economically viable solutions for a low-CO2 cement based materials industry, UN Environmental Programme, explains that low-clinker cement technologies provide the clearest path to decarbonising the cement industry. They provide low cost, scalable and immediate solutions to a huge issue – clinker process emissions. This is achieved whilst maintaining and even improving the technical performance of concrete, including its mechanical strength and durability. Importantly, by maximising the use of low-clinker, low-carbon cements, the burden on CCUS will be greatly reduced as there is far less CO2 produced in the first instance.