1e:T42b,A new kind of Ca-based regenerable CO2 absorbent, CaO/ Ca12Al14O33, was synthesized on the basis of the integration of CaO, as solid reactant, with a composite metal oxide Ca12Al14O33, as a binder, for applying it to repeated calcination/carbonation cycles. The carbonation reaction can be applied in many industrial processes, and it is important for practical calcination/carbonation processes to have absorbents with high performance. The cyclic carbonation reactivity of the new absorbent was investigated by TGA (thermogravimetric analysis). The effects of the ratio of active material to binder in the new absorbent, the mechanics for preparation, and the reaction process of the high-reactivity CaO/Ca12Al14O33 absorbent have been analyzed. The results obtained here indicate that the new absorbent, CaO/Ca12Al14O33, has a significantly improved CO2 absorption capacity and cyclic reaction stability compared with other Ca-based CO2 absorbents. These results suggest that this new absorbent is promising in the application of calcination/carbonation reactions.1f:T4b9,CO₂ capture and storage is a promising concept to reduce anthropogenic CO₂ emissions. The most established technology for capturing CO₂ relies on amine scrubbing that is, however, associated with high costs. Technoeconomic studies show that using CaO as a high-temperature CO₂ sorbent can significantly reduce the costs of CO₂ capture. A serious disadvantage of CaO derived from earth-abundant precursors, e.g., limestone, is the rapid, sintering-induced decay of its cyclic CO₂ uptake. Here, a template-assisted hydrothermal approach to develop CaO-based sorbents exhibiting a very high and cyclically stable CO₂ uptake is exploited. The morphological characteristics of these sorbents, i.e., a porous shell comprised of CaO nanoparticles coated by a thin layer of Al₂ O₃ (<3 nm) containing a central void, ensure (i) minimal diffusion limitations, (ii) space to accompany the substantial volumetric changes during CO₂ capture and release, and (iii) a minimal quantity of Al₂ O₃ for structural stabilization, thus maximizing the fraction of CO₂ -capture-active CaO.

	Year	Citations

References