Investigation of Y2O3/MxOy-Incorporated Ca-Based Sorbents for Efficient and Stable CO2 Capture at High Temperature

The control of anthropogenic CO2 emissions has attracted worldwide attention because of global warming. Among diverse carbon capture technologies, calcium looping (CaL) is proposed as a favorable approach for postcombustion CO2 mitigation. However, the sorbents capacitive loss with increased CaL cycling has severely limited the efficient application of the method. Therefore, obtaining sintering-resistant Ca-based sorbents with high capture capacity, fast capture kinetics, and superior stability is considered a research priority. Here, we reported our latest work on the development of a novel Y2O3/MxOy-modified Ca-based sorbent with superior CO2 sorption performance. Y20/Mg20, i.e., synthetic Ca-based sorbents with Y and Mg incorporated at the mass ratio of 1:1, achieved a significantly high conversion (above 90%) in 20 CaL cycles at a typical calcination temperature (similar to 900 degrees C) and was stabilized at the CO2 uptake of 0.311 g of CO2/g of sorbent even after 122 CaL cycles. A comprehensive investigation revealed that the outstanding performance arose from the characteristics of (1) superior surface area and pore volume, provided by pores with radii of <20 nm, (2) a gradually formed skeleton-type structure, and (3) a porous internal structure with a homogeneous distribution of Y2O3 and MgO nanoparticles.