Thermal transfer behavior of biochar-natural inorganic clay composite for building envelope insulation

In the context of sustainable development, the use of eco-friendly building materials has been considered as a solution to environmental pollution problems caused by fossil fuels. In this study, novel biocomposite were prepared using biochar and natural inorganic clay (NIC) to evaluate the applicability of biochar to buildings. After preparing the rice husk, coconut shell, and bamboo biochar, these were mixed into NIC at four ratios to form a board, and their morphological, thermal, and moisture performance were analyzed. Through morphological analysis using field-emission scanning electron microscopy, the microstructure of each biochar was confirmed, and the shape of each biochar was confirmed in the bio-composite mixed with biochar. As a result of TCi analysis, it showed that the maximum rate of decrease of thermal conductivity was 67.21% by biochar. As a result of dynamic heat transfer analysis, it was confirmed that it is less sensitive to thermal change due to low thermal conductivity of biochar. Also, the CUP test showed that the water vapor resistance factor increased up to 22.58% when mixed with biochar, which means that the biochar can reduce water vapor permeability. In conclusion, biochar can be used to make environmentally friendly and energy efficient building materials. (C) 2019 Elsevier Ltd. All rights reserved.