Preparation and performance of potassium-based sorbent using SnO2 for post-combustion CO2 capture

Abstract

Potassium-based sorbents using γ-Al2O3 or TiO2 as a support or an additive material have disadvantages in terms of their thermal stability and cyclic CO2 capture. To overcome the shortcomings of these sorbents, a novel potassium-based sorbent (KSnI30) using SnO2 was developed in this study. The KSnI30 sorbent formed only K2CO3 and SnO2 phases without any inactive alloy species even after calcination at high temperatures (500–700 °C), indicating the good thermal stability of the KSnI30 sorbent regardless of the calcination temperature. Furthermore, the KSnI30 sorbent has an excellent regeneration property (above 98 %), as well as high CO2 capture capacities (89–94 mg CO2/g sorbent). Its excellent regeneration property is due to the formation of a KHCO3 phase without by-products during CO2 sorption. These results of the present study demonstrate that the SnO2 shows promise as a new support or an additive material to replace TiO2 and γ-Al2O3 in the preparation of a regenerable potassium-based sorbent for post-combustion CO2 capture with good thermal stability and excellent regeneration property.