Abstract
Waste foundry sand (WFS) is a by-product of the casting industry, which poses increasing economic and environmental issues due to the costs associated with landfill maintenance and stricter environmental regulations. This study proposes a novel solution for WFS as a material for thermal energy storage. The approach involves blending WFS with NaNO3 and a proprietary additive, X, to fabricate a composite phase change material (CPCM). The CPCM is found to be structurally stable up to 400 °C, and an optimal composition with a mass ratio of NaNO3:WFS:X = 0.6:0.3:0.1 is achieved. This composition yields an energy storage density of 628 ± 27 kJ/kg, and an average thermal conductivity of 1.38 W/mK over the temperature range of 25–400 °C. The CPCM also exhibits good mechanical strength and a low coefficient of thermal expansion compared to NaNO3. Currently, only a small portion of WFS is recycled, most commonly in building applications. The CPCM presented in this study has the potential for medium-to-high temperature heat storage in waste heat recovery applications, offering a sustainable solution for upcycling WFS.
Original language | English |
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Article number | 112294 |
Number of pages | 9 |
Journal | Solar Energy |
Volume | 268 |
Early online date | 28 Dec 2023 |
DOIs | |
Publication status | Published - 15 Jan 2024 |
Bibliographical note
Funding Information:The authors would like to acknowledge Transforming Foundation Industries Network + in the context of THERMCAST (EPSRC grant EP/V026402/1) as well as the European Commision under Grant agreement ID: 101068507.
Keywords
- Composite
- Foundry sand
- Latent heat storage
- Phase change
- Upcycling
- Waste heat recovery
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- General Materials Science