Waste Semi-coke Ash for Fabrication of Form-Stable Phase Change Materials for Thermal Energy Storage

Massive accumulation of solid waste semi-coke ash (SCA) produced in industrial processes will damage local environment. To recycle SCA and fabricate low-cost thermal energy storage materials, the idea of fabricating the form-stable phase change materials (FSPCMs) with SCA as skeleton material and solar salt (SS) as phase change material was proposed innovatively. Seven FSPCMs with different SS content were prepared by compression and sintering method, and key performances were investigated by differential scanning calorimetry, constant-speed pressurization method, scanning electron microscopy, sessile drop method and X-ray diffraction. The research found that the sample A55 with 50 wt% SS showed the best performance; the thermal energy storage density of sample A55 was 483 J/g in the range of 100 to 450 °C; the compressive strength of sample A55 reached 86.12 MPa; the sample A55 had excellent chemical compatibility and thermal stability.