Thermochemical Energy Storage Performances of Steel Slag‐Derived CaO‐Based Composites

Abstract

Low-cost and easily scaled-up acidification is a potential synthesis approach to produce CaO-based composites derived from steel slag for thermal energy storage/release via multicyclic calcination/carbonation. Acid concentration, acidification temperature, and acidification duration were comparatively investigated. The cyclic thermal energy storage/release properties of such composites are closely related to the acidification parameters, mainly attributed to the differences in the composition of the synthetic composites under different acidification conditions. The synergistic effect of the increased Ca and Mg content as well as the reduced content of Si and Fe within the composites contributes to improve their cyclic thermal energy storage/release performance.

Development of Thermochemical Heat Storage Based on CaO/CaCO3 Cycles: A Review

“…In the abovementioned acetic acid treatment process, a filtration step was added to remove silicon impurities, which could increase the effective conversion of the waste residue after treatment to about 0.60. Bai et al [119] also reported the influence of different acidification parameters, such as acid concentration, acidification temperature, and acidification time on the heat storage of calcium-based composites derived from steel slag. Among them, after the steel slag was acidified with acetic acid, the contents of Ca and Mg increased, while the contents of Si and Fe decreased, which improved its cyclic stability.…”