CO2 adsorbent for sustainable development: synthesis route and performance study of slag-derived layered double oxides.

Metallurgical slag contains numerous valuable components, but its low utilisation rate has caused significant environmental issues. The synthesis of a slag-based CO2 adsorbent was beneficial for treating solid waste and achieving the carbon peak target of the iron and steel industry. In this study, layered double oxides synthesized from blast furnace slag were employed for CO2 adsorption, and the adsorption performance and industrial application stability were investigated. The breakthrough time and adsorption capacity of adsorbent were 13.67 min and 2.44 mmol‧g-1, respectively. The concurrent adsorption of SO2 affected CO2 adsorption, whereas H2O(g) contributed to the two adsorption processes. Therefore, research on the antisulfur modification of layered double oxides and flue gas desulfurization is necessary for decarbonisation. Considering the effect of multicomponent flue gas on the adsorbent, the number of service cycles of the adsorbent should theoretically not exceed 6, resulting in preferable regeneration performance such that the adsorption capacity reaches 65% of the initial condition within that range. Finally, this novel work offered an innovative path for achieving high-value-added utilisation of blast furnace slag and carbon reduction in the iron and steel industry.