Development of ternary blended cements (LC³) to be applied as thermal energy storage material in concentrated solar power plants

Abstract

Currently, there is great awareness of the increase in energy consumption, dependence on fossil fuels, and greenhouse gas emissions, particularly CO2. One of the largest sources of carbon dioxide emissions is the cement and concrete industry, which has been growing in recent years. Therefore, it is necessary to implement measures to limit the global pollution caused by this sector. Furthermore, with the development of renewable energies, there is a growing need to develop batteries and materials that allow to store this energy for later use. Therefore, the main objective of this study is the development of ternary blended cements (LC3), in which clinker is partially replaced by thermally and mechanically activated kaolinitic clay, to be implemented as a thermal storage material in CSP plants. The development of the alternative cements was carried out in the laboratory and a full characterization was performed to evaluate their physical, mechanical, and thermal properties. In addition, a comparison of these properties with Portland cements was performed, to evaluate whether the characteristics presented met the required needs. Therefore, LC3 cements have affordable energy storage capacity to be implemented as TES media. In addition, LC3 cements have the same storage capacity as OPC, and it is maintained after aging test. Finally, an LCA was performed to quantify and evaluate the reductions provided by LC3 in terms sustainability reduction impact in the environment to be using this alternative cement in comparison with the common one. The results showed that both the mechanical and thermal properties of the cements are in line with the expected values and allow their use as TES materials regarding the energy storage capacity, energy density and energy performance by achieving and environmental impact reduction up to 22,6 %. Therefore, this study confirms that LC3 cement is more sustainable cements that significantly reduce CO2 eq. emissions (up to 24 % reduction).