Removal of CO2 by CaO/MgO and CaO/Ca9Al6O18 in the Presence of SO2

Sorbents with their components CaO/MgO and CaO/Ca9Al6O18 were produced from calcium d-gluconate monohydrate, magnesium d-gluconate hydrate, and aluminum l-lactate hydrate as precursors with a simple wet mixing method. The effects of sorbents type, mass proportion, SO2 concentration, and calcination temperature on sorbent capability were studied. The results show that CaO/MgO (75:25%, w/w) kept the best CO2-capture capability, while CaO/Ca9Al6O18 (75:25%, w/w) kept the best cyclic stability. The CO2-capture process is drastically blocked when SO2 exists. The CO2-capture capacity drops quickly when the SO2 concentration is promoted. However, the cumulative SO2-capture capacity increases at the same time. The total calcium use rises tenderly after many cycles, and the tendency becomes more obvious with an increasing SO2 concentration. The effect of the calcination temperature on CaO/MgO and CaO/Ca9Al6O18 absorption characteristics shows little difference.