Abstract
Thermal energy storage (TES) is essential for sustainable energy solutions. This study investigates the potential of metal industry waste for TES applications. Experimental findings indicate that while the sludge is not suitable for latent or thermochemical storage due to the absence of phase transitions and water sorption properties, it exhibits a noteworthy heat capacity. Specifically, the sludge demonstrates a TES capacity of 42 Wh/kg within a temperature range of 100 °C, making it a potentially viable option for sensible TES, particularly in building applications. To enhance its performance, integrating the sludge with other materials to improve thermal conductivity is recommended. This research underscores the significance of repurposing waste materials for TES, emphasizing the importance of sustainable practices and reevaluating waste streams for long-term environmental benefits.