(217ea) Study On the Attenuation of Ca-Based Sorbents Cyclic Carbonatation Rate

The cyclic calcination/carbonation reaction(CCCR) of Ca-based sorbents is a novel, cheap and effective method for CO₂ capture. The cyclic carbonation rate of Ca-based sorbents (X_N) reduces with the increase of cyclic reaction times. Particularly, the calcination temperature and absorbent mineral composition are especially significant to the cyclic carbonation rate of Ca-based sorbents. A controlled atmosphere furnace is used as test equipment for simulating suspension state, the effect of absorbent mineral composition and calcination temperature on the cyclic carbonation rate of Ca-based sorbents is investigated. Then, the microstructure and morphology of the absorbent are analyzed by the mercury injection apparatus and scanning electron microscope SEM. Results show that the original structure of absorbent is non-porous, it can produce pore of beneficial to absorb CO₂ only after calcination reaction. Compared to the pure limestone, some dolomite in limestone can effectively slow down the particle sintering and attenuation of small pore and pore area. So, its cyclic carbonation rate is higher and the attenuation amplitude is small. In addition, the cyclic carbonation rate of Ca-based sorbents decreases with the rise of calcination temperature, especially when the temperature increases over 1000℃, the attenuation of small pore and pore area of absorbent is severe with cyclic reaction.