Cement plant technologies have evolved a lot in recent years. Energy consumption is an important part of the direct variable costs of cement plants, and therefore a key factor of profitability. Recent technological developments have permitted operators to reduce energy consumption by around 25% (around 3 GJ/ton) (© OECD/IEA, Technology Industry 2009). The lifetime of cement plants averages 50 years, so the main challenge here is to renovate existing installations. As in other industries, the optimization of the heating process is key to improving energy performance. The introduction of preliminary heating could help reduce temperature gradients and therefore the energy required. The use of cooler grates instead of rotating coolers would also improve energy performance. Furthermore, reusing the heat dispersed to produce electricity (which could then be used back in the heating process) is an important opportunity to optimize energy consumption and waste. Using variable speed drives to adjust to the particularities of the process execution and the materials used would also help optimize in real-time the execution of the process. Finally, using waste or biomass as a replacement for fossil fuels is another way to reduce primary energy consumption. This is already widespread in OECD countries but has yet to be deployed elsewhere.
Finally, as in steel foundries, CO2 capture systems are a possible option for reducing greenhouse gas emissions by cement plants.