Synthesis and Characterization of CaO Nanopods for High Temperature CO2 Capture

A hollow structured CaO sorbent with high CO 2 absorption capacity and good cyclic performance at high temperatures was derived from the corresponding CaCO 3 precursor, which was prepared by bubbling gaseous CO 2 through a Ca(OH) 2 slurry in the presence of the triblock copolymer surfactant, P123 (PEO 20 PPO 70 PEO 20 ). Field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images showed the novel sorbent to be comprised of nanosized platelets forming hollow particles resembling a pod of approximately 200 nm in diameter and up to 600 nm in length. Thermogravimetric analysis showed that the tailored sorbent had the highest CO 2 absorption capacity when compared with calcines derived from precipitated CaCO 3 without P123 and a commercially available CaCO 3, retaining >50% CO 2 absorption capacity after 50 CO 2 capture-and-release cycles for carbonation temperatures from 600 to 700 °C.