THERMAL PROPERTIES EVALUATION OF PCM AND BIOCHAR APPLIED IN TERIOR FINISHING MATERIALS

This biochar is a porous carbon material produced through thermochemical conversion of organic materials under oxygen-depleted conditions. Adding biochar to building materials can store and fix carbon in structures for decades, and this carbon sequestration helps to balance the global carbon cycle. A PCM is a latent heat thermal energy storage material that can store and release heat as heat of fusion or solidification during the phase change process. This experiment aims to improve the thermal performance of artificial stone finishes used as interior veneers. A phase change material (PCM) with a high latent heat performance and biochar, an eco-friendly material, were used in the experiment. n-Octadecane was incorporated into lightweight aggregates; spruce tree(ST), rise husk(RH), and miscanthus straw(MS) biochars were utilized. The fabricated specimens exhibited clear peak temperature and latent heat values depending on the PCM used. In terms of strength characteristics, the specimens with biochar up to 4% showed equivalent or higher compressive strength to those without biochar, and the use of 6% biochar was associated with a decrease in strength. In addition, the thermal conductivity of the specimen decreased as more biochar was mixed, and it was found to decrease in the order of RH, ST, and MS biochar. Through the heat transfer test, the heat storage performance of the specimens and the temperature delay effect (of approximately 2.7 h) were verified. When using ST, RH, and MS biochars, the peak temperature decreased by approximately 4-5 °C compared to the PAS test sample without biochar. An artificial stone with an integrated PCM can be effectively used for peak temperature control based on the heat storage performance. When an appropriate amount of biochar is applied, a consistent level of strength can be maintained and the thermal conductivity can be improved. The appropriate proportion of biochar was found to be within 4% of the weight of the cement. Using biochar that reuses waste provides an environmental advantage, and a biochar specimen can enable efficient use of thermal energy and room temperature control.