Effect of carbon capture on carbide slag-steel slag shape-stable phase change materials for thermal energy storage

For resource utilization of industrial solid waste, a 1:1 mixture of carbide slag-steel slag was innovatively selected as the carbon sequestration material for CO2 sequestration in this work, and the carbon sequestrated carbide slag-steel slag material was used as skeleton material to make carbon sequestered carbide slag-steel slag/NaNO3 phase change composites. The carbon sequestration and thermal storage properties of the materials were characterized. The results showed that the carbon sequestration rate of the carbide slag-steel slag hybrid material could reach 24.48 %. The thermal storage density of sample C-SC4 reached 444.2 J/g, the thermal conductivity was 1.057 W/(m-K), and the mechanical strength was 142.2 MPa. Compared to sample SC4 without carbon sequestration, the thermal storage density increased by 19.7 %, the thermal conductivity decreased by 27.5 %, and the mechanical strength increased by 8.4 %. After 1440 heating/cooling cycles, sample C-SC4 still has excellent chemical compatibility and thermal storage properties. The unit thermal storage cost of C-SC4 is 3.34 $/MJ, significantly lower than that of other composites, showing great commercial potential. This research opens a new way for the preparation of phase change composites by utilizing industrial solid waste as skeleton material, helps to promote the rapid development of the composite thermal storage industry.