Efficient MgO-doped CaO sorbent pellets for high temperature CO2 capture

Novel MgO-doped CaO sorbent pellets were prepared by gel-casting and wet impregnation. The effect of Na+ and MgO on the structure and CO2 adsorption performance of CaO sorbent pellets was elucidated. MgO-doped CaO sorbent pellets with the diameter range of 0.5-1.5 mm exhibited an excellent capacity for CO2 adsorption and adsorption rate due to the homogeneous dispersion of MgO in the sorbent pellets and its effects on the physical structure of sorbents. The results show that MgO can effectively inhibit the sintering of CaO and retain the adsorption capacity of sorbents during multiple adsorption-desorption cycles. The presence of mesopores and macropores resulted in appreciable change of volume from CaO (16.7 cm(3)center dot mol(-1)) to CaCO3 (36.9 cm(3)center dot mol(-1)) over repeated operation cycles. Ca2Mg1 sorbent pellets exhibited favorable CO2 capture capacity (9.49 mmol center dot g(-1)), average adsorption rate (0.32 mmol center dot g(-1)center dot min(-1))and conversion rate of CaO (74.83%) after 30 cycles.

Automated summary

Novel MgO-doped CaO sorbent pellets exhibit excellent CO2 adsorption capacity and adsorption rate due to the homogeneous dispersion of MgO and its effects on the physical structure of sorbents, effectively inhibiting sintering of CaO and retaining adsorption capacity during multiple cycles. Mesopores and macropores contribute to significant volume changes during operation cycles. Ca2Mg1 sorbent pellets show favorable CO2 capture capacity, average adsorption rate, and conversion rate of CaO after 30 cycles.