Life Cycle Assessment of Solar Cement Production Incorporating Solar Heat and Calcium Looping

Abstract

The cement industry is one of the largest emitters of CO₂ due to fossil fuel combustion and limestone calcination in its production process. The integration of concentrated solar thermal energy to drive the calcination process offers a promising decarbonisation strategy within this industry. This study evaluates the environmental performance through a Life Cycle Assessment (LCA) of solar-assisted cement production incorporating a solar calciner for reducing fossil fuel demand and a carbonator for CO₂ capture. A cradle-to-gate study was conducted with a functional unit of 1 ton of cement production, comparing three scenarios: a conventional cement plant (SC1), a solar calciner replacing the fossil fuel-based calcination process in a conventional cement plant (SC2), and an integrated system with a solar calciner and a carbonator for CO₂ capture (SC3). The results indicate that substituting fossil fuels with solar heat significantly reduces CO₂ emissions, demonstrating the potential of concentrated solar thermal technologies in decarbonizing such a high-temperature industrial process. Further reductions in climate change were observed after a carbonator was installed to capture process- and combustion-related CO₂ emissions. However, environmental trade-offs were exhibited in certain impact categories due to increased material and infrastructure requirements of the carbonator unit. Overall, the thesis highlights the effectiveness of implementing renewable energy sources and CO₂ capture technologies in reducing the carbon footprint of cement production, while emphasizing the importance of considering broader environmental impacts during the transition to a sustainable cement industry.