Element doped sodium-based sorbents with high attrition resistance and CO2 capture capacity during CO2 sorption/desorption processes

Abstract

The technology of removing CO2 from coal-fired power plants by sodium-based sorbents has received increasing attention. However, the researches on sodium-based sorbents both with high CO2 capture capacity and attrition resistance are still insufficient, which hindering the industrial applications of the sodium-based sorbent. This paper is devoted to solve this problem. Different elements, including Zr2+, Mg2+ and Ca2+, were separately doped in the sorbent and the corresponding CO2 sorption and attrition resistance performances were studied. Under the desired doping content (1–15 wt%), Zr2+, Mg2+ and Ca2+ improved the mechanical strength of the sorbent with the order of Zr2+ < Mg2+ < Ca2+, while the corresponding CO2 sorption capacity of the sorbent were improved with the order of Zr2+ < Ca2+ < Mg2+. NaAlMg15, with 15 wt% of Mg doping, performed good CO2 sorption and attrition resistance due to that doping 15 wt% of Mg increased the alkaline sites and changed the cellular structure, which enhanced the strength of the sorbent. Finally, extrusion-spheronization method was used to fabricate the spherical sorbent with NaAlMg15, which exhibited excellent attrition resistance and CO2 sorption performances.