LAUSR

Abstract The rapid loss-in-capacity in CO2 capture is the major barrier to the application of abundantly available CaO-based natural minerals in calcium looping process. In this work, the mechanically activated method of wet ball-milling was tried to prepare highly efficient CO2 sorbents from naturally occurring dolomite. Two major operation parameters, ball-milling duration and solid-to-liquid ratio, closely affecting the characteristics of wet ball-milled dolomites were investigated. It is found that the prolongation of ball-milling duration is beneficial to improve the cyclic CO2 capture capability of wet ball-milled dolomite. The solid-to-liquid ratio of 1:1 is optimum to control the aggregation of dolomite particles during ball-milling process. Therefore, the dolomite milled with a solid-to-liquid ratio of 1:1 for 120 min exhibits highly stable CO2 capture performance under severe calcination conditions, achieving a high carbonation conversion of 74.8% in the 25th cycle. The superior CO2 capture performance of wet ball-milled dolomite is mainly attributed to the appreciably reduced particle size and preserved porous microstructure, which promote the accessibility of CO2 to the interior, free CaO.