Expanded Graphite Addition to Enhance the Thermal Conductivity of PCMs for Heat Storage Applications

The stringent necessity to reduce global warming and energy consumption strongly involves the building sector, which is responsible for 30% of greenhouse gas emissions and 40% of the overall world energy consumption. International agreements and regulations stimulate the identification of new solutions for the containment of emissions and energy use. Thermal energy storage (TES) using phase change materials (PCMs) is one of the most interesting solution to achieve this goal. In the last decade, these materials have been deeply studied in order to improve their energetic performance. In particular, thermal conductivity must be enhanced. For this purpose, in this work, a new generation of PCMs, made by fatty acid mixed with graphite (G-PCMs), is presented. Latent heat and thermal conductivity of G-PCMs and those of their bases (Lauric and Myristic fatty acids) are compared, showing good capabilities of G-PCMs to enhance heat exchange properties of thermal storage in buildings.