Katish, et al (2024) Experimental study of phase change material (PCM) biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More composite for net-zero built environment applications. Cleaner Materials. https://doi.org/10.1016/j.clema.2024.100274

Biochar combined with phase change materials (PCMs) shows promising potential in sustainable construction. Recent research explores integrating octadecane PCM into biochar to create composites for use in building materials such as mortar and gypsum. The composite’s primary purpose is to improve thermal energy storage, which can reduce the energy required for heating and cooling buildings, aligning with net-zero goals.

The study finds that using vacuum impregnation achieves a high PCM loading of 62.21%, allowing the biochar-PCM composite to store and release substantial thermal energy (116.7 J/g). The material’s thermal performance was validated through various analyses, confirming that PCM remained well-retained within biochar pores, with minimal leakage observed at elevated temperatures.

The integration of PCM-biochar reduced the compressive strength of mortar by up to 45.5% initially. However, after 120 days, a strength recovery to 43 MPa was observed. Although the composite’s mechanical properties were compromised, they remained within acceptable limits for structural applications, especially in retrofitting. The study showed a reduction in thermal conductivity, beneficial for insulation, alongside an increase in specific heat capacity, enhancing the composite’s energy storage capability.

While the trade-offs in mechanical strength indicate that careful balance is essential for structural applications, the biochar-PCM composite provides a promising route to improving building materials’ thermal management and sustainability.