A novel candidate shape-stabilized phase change material for building energy conservation based on lauric acid/roasted iron tailings-expanded graphite

Abstract

This study presents the fabrication of a novel shape-stabilized phase change material (SSPCM) characterized by high thermal capacity and heat transfer efficiency. The material was composed of lauric acid (LA) embedded in roasted iron tailings (RIT) and expanded graphite (EG), utilizing a straightforward, low-cost, and direct impregnation method. The as-prepared LA/RIT-EG SSPCM underwent a comprehensive analysis of leakage tests, surface morphology, chemical compatibility, phase change properties, thermal stability, and reliability. Furthermore, the heat transfer efficiency and thermal conductivity were measured through cooling tests and a laser thermal conductivity analyzer, respectively. The LA/RIT-EG formulation demonstrated an ability to absorb 61.57 wt% LA without leakage, maintaining excellent form-stability with a mass fraction proportion of 29:9.43 for RIT and EG. DSC results revealed phase temperatures and latent heats of 42.49–46.31 °C and 108.1–113.1 J/g, respectively. Compared to pure LA, LA/RIT-EG exhibited a 489.7 % increase in thermal conductivity. Additionally, heat storage and release rates were improved by 81.25 % and 88.24 %, respectively. The study elucidated the mechanism behind the enhancement in encapsulation capacity and thermal conductivity by RIT-EG, validated through specific surface area and wettability tests. Overall, the results suggest that LA/RIT-EG, characterized by high thermal capacity and heat transfer efficiency, holds promise as a potential candidate for thermal energy storage, particularly in the context of energy conservation in buildings.