Stabilized CO2 capture performance of wet mechanically activated dolomite

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 ballmilling 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.