Enhancing sustainability and energy savings in cement production via waste heat recovery

Abstract

Cement production is one of the most energy-intensive industries. During the clinker formation and cooling processes, excess heat is lost to the atmosphere. For this reason, using waste heat to generate useful energy is considered the most promising approach to sustainable cement production. Many cement plants still face challenges in energy efficiency due to historically low energy prices and subsidies in Uzbekistan, which have deterred the adoption of waste heat recovery (WHR) technologies. This study conducts a techno-economic analysis of WHR technologies for a cement plant with an annual capacity of 1 million metric tons (Mt). It evaluates potential energy savings and economic benefits, identifying key waste heat sources, such as preheater flue gas and clinker cooling air, with a total recoverable waste heat of 60.52 MW. The implementation of WHR systems can significantly enhance energy efficiency and reduce operational costs. Results show that WHR can reduce clinker production costs by 3.81% and the levelized cost of clinkers by 7.49%, while cutting annual indirect CO2 emissions by 63.26%. Given the legislative support and recent energy price liberalization, the first WHR projects are expected to start in 2025 in Uzbekistan. This analysis offers valuable insights for adopting WHR technologies to improve sustainability and competitiveness in Uzbekistan’s cement industry.