Engineering a Novel Ceramic Composite for High-Temperature Thermal Insulation

Thermal insulations play a pivotal role in energy conservation and carbon footprint reduction by mitigating energy losses at elevated temperatures. The thermal insulation of large energy systems faces challenges of in situ application and rise in thermal conductivity of the insulation with the increasing application surface temperature. This work develops, characterizes, and investigates a high-temperature ceramic composite (HTCC) insulation to address these challenges for high-temperature (≥300 °C) applications. Ceramic wool fiber, hollow ceramic microspheres, and silica form a multiscale porous structure in the HTCC that minimizes heat loss at high temperatures due to the infinite hot plate effect and phonon scattering phenomena. The rise in thermal conductivity for HTCC is 38%, whereas for conventional insulation, ceramic fiber (CF) it is 56%, when the application temperature increases from 300 to 500 °C. Moreover, the thermal diffusivity of the developed composite is 58% lower than CF. The efficacy of the HTCC is investigated experimentally using a model of thermal energy storage. The HTCC insulation, at 55% less thickness, reduces the heat loss by 37%, saving around 4780 kWh m⁻² yearly compared to conventional insulation. Significant energy savings are expected when HTCC is applied to large-scale industrial energy systems.