One-Step Synthesis of Structurally Improved, Al2o3-Supported K2co3 Pellets Via Graphite-Casting Method for Low-Temperature Co2 Capture

The desirable CO2 adsorption capacity and mechanical property are both important for the large-scale industrial applications of K2CO3-based CO2 adsorbents. In this work, graphite-casted, Al2O3 -supported, K2CO3-based pellets were prepared for CO2 adsorption. The prepared K2CO3-based pellets containing 30 wt % of K2CO3 calcinated at 900 oC exhibites CO2 adsorption capacity of 1.4 mmol/g, which is over 2.5 times that of the pellets calcinated at 300 oC. It is mainly attributed to the residual graphite coating on the surface of the K2CO3-based pellets calcinated at 300 oC, which inhibits the diffusion of H2O due to the hydrophobicity of graphite and further causes the poor carbonation performance. Moreover, the addition of 40 wt % of microcrystalline cellulose can further enhance the adsorption capacity of the graphite-casted K2CO3-based pelelts to ~1.95 mmol/g due to the improved microstructure. Additionally, the structurally improved K2CO3-based pellets also exhibit desirable mechanical property with a compression strength of 69.45 Mpa. Comprehensively considering the simple and easily scaled-up preparation route of graphite-casting method, the structurally improved, graphite-casted, Al2O3-supported, K2CO3-based pellets possess potential practical application prospect