CaO-based sorbents for CO2 capture prepared by ultrasonic spray pyrolysis

We report the ultrasonic spray pyrolysis (USP) synthesis and characterization of composite calcium oxide-based sorbents for carbon dioxide capture. Inclusion of a small amount of Al2O3 into the CaO matrix (as low as Al/Ca: 0.03) yielded significant enhancement of resistance to recycling degradation. The effective homogenous dispersion of additives in the CaO matrix and the relatively high surface area materials obtained via USP explain the sorbent's high performance. All materials were characterized by XRD, STEM, TEM, SEM, and TGA (for CO2 uptake measurements). Two common phases of CaAlxOy, Ca12Al14O33 and Ca3Al2O6, were formed during multiple cycles of calcination and CO2 uptake.